Improving Response Procedures to Natural Gas Emergencies

By Jerry Knapp and Daniel Moran

The contractor was using an underground boring tool when he hit and penetrated the plastic two-inch, 60-pound natural gas street main in a residential area of modular row houses. This pneumatically powered boring device pounded its way through the soil, tunneling from a trench on one side and under the roadway to the other side to reduce the cost of installing, in this case, a communication line. Natural gas leaked for an undetermined time and eventually leaked back into one of the nearby homes. The West Haverstraw (NY) Fire Department responded to this incident on January 16, 2012.

Knapp: My captain and I were checking nearby homes for gas with a four-gas meter, a common task for fire departments. The gas company technicians had been on the scene almost as long as the fire department, about 45 minutes prior to the explosion. We had not found any evidence of gas in any of the homes (I had our four-gas meter and a six-foot hook); there was not even an odor. The last home was locked. Based on a request by the utility technician to get in the house, we were waiting for a team with the forcible entry tools when the trapped gas inside exploded, completely shredding the house.

Instantly, it was no longer a routine gas leak. I saw something white fly over my head; it may have been the front door or the front wall of the house. It landed across the street. I saw the house come apart. At times like this, your mind goes into hyperdrive. It is impossible to explain, but your mind is working superfast, and your vision is simultaneously seemingly in super-slow motion.

The house exploded in a microsecond; but as I saw it happen in slow motion and instantly, I just knew it was going to be bad, deadly bad. I was completely at the mercy of the incident. My feet were now several feet off the ground. Then, suddenly, I was on my hands and knees staring down at the curb, wondering about a lot of things – primarily, how did I get here? I was close to the house; now I am at the curb. I don’t remember the flight, but I am burned, bleeding, and confused; and it is deadly quiet. Am I dead? Bright red blood dripped from my head and pooled on the asphalt below me. My heart was still pumping; “That’s good,” I thought. It seems like an eternity. I am alone, more alone than I have ever been. Smoke, dust, and blood are my smothering companions. Emotions suddenly overran everything! Anger filled my every void. My thoughts ran wild: “Is it my destiny as a firefighter to die in this street among this trash?” I was looking at a roll of toilet paper on the road in front of me. “Am I to die without even saying goodbye to my wife and son? It was just a routine and annoying gas leak. What happened?”

Firefighter voices suddenly overtook the scene now. There was a chorus of terror-filled screams: “Where is Kenny?” I looked up and saw that they were dragging Captain Kenny Patterson lifeless from under the rubble of the house in the side yard. I thought, “Surely, he is dead.” I wondered, “Am I dead, too?” Then, I heard the captain scream. At least now I knew that he has a chance of living. The emotional and spiritual roller coaster that followed that nonroutine gas leak changed our lives forever.

Patterson and I survived our burns, broken bones, concussions, numerous injuries, and mental bruises, but it took a very long time. Those times of intense anger, the emotional dives, and spiritual experiences drove me to use that long recovery time to learn why this incident went bad and what we can do to respond to natural gas leaks more safely?

Moran: Recognizing the importance of Jerry’s goal, I became an active partner in this study. In this article, and the two to follow in succeeding months, we will share valuable lessons learned from this explosion and our four years of research. Our goals follow:

  • To improve your tactical situational awareness at natural gas emergencies.
  • To provide you with critical strategic decision-making information.
  • To improve your existing gas emergency response procedures.
  • To provide training methods that will enhance your officers’ and firefighters’ actions during natural gas emergencies.

Tactical Awareness

Rockland County’s 26 fire departments respond to more than 500 gas emergencies each year. Because it is a very common call for us, firefighters do not always have a “respect” for the potential dangers involved. The reason for this is obvious: We have been dispatched to numerous gas leaks, odors of gas, and so on. Typically, it is a pilot light out or a very minor leak. One reason we are called to these leaks that are so minor is that humans can detect very tiny amounts of the odorant in natural gas. This is in accordance with Federal Regulation 49 CFR 192.625, which states: “A combustible gas in a distribution line must contain a natural odorant or be odorized so that at a concentration in air of one-fifth of the lower explosive limit, the gas is readily detectable by a person with a normal sense of smell.”

The flammable range for natural gas is four to 14 percent in air, and one percent gas in air equals 10,000 parts per million (ppm). Many gas suppliers use five to 15 percent for the flammable range. The variation depends on the exact mixture of gases in addition to the methane. For the fire department, our concern is usually what percentage of the lower explosive limit (LEL) is measured by air monitoring. In ppm, the flammable range is 40,000 to 140,000 ppm or 50,000 to 150,000 ppm.

<img src="/content/dam/fe/print-articles/2017/03/1703FE-Knapp_Photo_1.jpg" alt="(1) Routine gas leaks can turn deadly instantly. (Photos by Dominick D’Alisera.) “>
(1) Routine gas leaks can turn deadly instantly. (Photos by Dominick D’Alisera.)

Recall that natural gas has no odor. The odorant, usually some form of methyl mercaptan, is detectable at 0.002 ppm by most humans, according to the U.S. Centers of Disease Control and Prevention (CDC). The CDC also reports that “students accidentally exposed to about 4 ppm of methyl mercaptan for several hours experienced headaches and nausea.”1 These numbers indicate that humans are very sensitive to the odorant and it will produce noticeable symptoms at very low levels.2 According to the Pipeline and Hazardous Materials Safety Administration (PHMSA), most people can detect it at one ppm. As a comparison, the odor threshold for chlorine is 0.2 ppm, which is 100 times greater than that of natural gas odorization.3

In addition to the odor, the following observations may indicate that the gas leak may have existed for a longer term. You should note them in your size-up and consider them when devising tactics.

  • Vegetation in the area of a gas leak may improve or deteriorate.
  • Insects may migrate to areas of leakage caused by the microbial breakdown of some of the gas components.
  • Fungus-like growth, especially in valve boxes and manholes, may indicate gas leakage caused by the lack of oxygen. It may be white to gray in color and look like frost.4

Some Potential Hazards

The incidence of civilian and firefighter deaths and injuries at natural gas incidents cannot be overstated. On September 27, 2016, Fire Department of New York Battalion Chief Michael Fahy was killed when a two-story home exploded about an hour after the call for a gas odor was received. Six police officers were also hospitalized with minor injuries. The chief was in the street directing operations when the home exploded. He was hit by debris.5

On October 7, 2016, at least four people were killed after an apparent gas explosion (propane) occurred at a duplex on the Pine Ridge Indian Reservation in South Dakota. Allegedly, residents smelled propane and were searching for the leak before the explosion. (5)

A February 2011 gas explosion in Allentown, Pennsylvania, killed five civilians, injured six, caused the evacuation of 500 people, and destroyed two homes by explosions and six others in the subsequent fire because the gas could not be shut off. 6

Also in Allentown, a home exploded on August 8, 1976. When engine companies arrived, they found one house completely leveled and began to fight the resulting fire. While personnel were operating at the scene, the home across the street exploded, trapping two firefighters in the debris and resulting fire; Lieutenant John McGinley and Firefighter William Berger succumbed to their injuries. (6)

First Actions at a Natural Gas Response

At a natural gas emergency, immediately establish a hot zone, just as you would for a hazmat call. This is a step you can institute immediately as part of your standard operating procedures (SOPs). In the case of an explosive gas, this hot zone can more appropriately be called the “Kill Box.” The Kill Box refers to the area around the building in which responders likely would be killed if a gas explosion were to occur. You may be hit with flying glass, other fast-moving parts of the building, or even falling energized wires. Luck, faith, or fate will determine if it means certain death. Compare the experience of Knapp and Patterson in the explosion described at the beginning of this article with that of Fahy. All were outside of the building in similar positions. Fahy died; the other two did not.

In photo 3, the header board (about 70 pounds) did not slowly roll along the ground when the gas inside the house exploded. It was blasted from the home and flew at some height above the ground, through the Kill Box, and across the yard and crashed into the street. This and other much smaller debris (glass metal fragmentation) can kill you if you are in its path. Stay out of the Kill Box at gas jobs just as you stay out of the collapse zone at fires and the hot zone at hazmat calls.

A position that may also give some protection is the area off the corners of the building. Certainly, there is no guarantee, but the walls of a home tend to be blown outward, leaving the classic “V” shaped void in the Kill Box off the corners of the home. In photo 2, there is a clear void of significant debris off the A-D corner. Our turnout gear is not rated for flying building parts, massive projectiles like header boards, shards of glass, or explosions of any kind.

The terminology “Kill Box” has other practical and safety implications. First, it sets the entire crew’s approach to the call – assume the worst possible outcome until proven otherwise. Is this not similar to what we do for automatic alarms? We send a full box alarm response until we get there and prove there is no emergency. How many times have we done that? Similarly, many fire departments always conduct a primary search and consider the building occupied until they prove otherwise. At natural gas emergencies, strategically plan for the worst case until your size-up, meter readings, and “life safety first” procedures prove otherwise.

Plan B

It may seem like an overreaction to always assume this routine and annoying call could have an explosive ending for you and your crew. Design your Plan A to minimize the risks to your crew by taking manageable risks. It is important to realize that if you roll into a natural gas call and assume it will be the routine gas leak call where “nothing ever happens,” you are betting your life on that assumption. You will be right the vast majority of the time. However, as Deputy Chief Billy Goldfeder ( commented regarding the Knapp-Patterson close call cited at the beginning of this article, “I bet you have been to hundreds of gas leaks. That last one was a bear, wasn’t it?” Complacency has no place at these calls.

Tactical Actions

Following are some tactics to follow at an incident involving natural gas:

  • Ensure that your SOPs are written so that they do not allow apparatus to be driven into the Kill Box on these calls. If you are dispatched to 3 Main Street for an alarm, do not set up in front of that address. Park the rigs a house or two outside the Kill Box.
  • Your procedures should limit the number of personnel in the Kill Box. How many firefighters and officers does it take to get meter readings or interview the caller? Do you need to send in the entire company? Firefighters tend to accumulate in small herds. Have the tactical awareness to stay out of the Kill Box unless you need to be there. Officers are responsible for keeping unnecessary members out of the Kill Box.
  • Be tactically aware. You are at a release of an explosive gas in a contained area (building) that has numerous ignition sources – in other words, you are responding to a potential bomb, a big bomb. Imagine you are the officer in charge on arrival and the police officer comes to your rig and says, “I think I saw a bomb on the living room floor; could you go over to the window and look in and see if you agree?” What would you tell him? We need to respect the potential explosive outcome of all gas leaks when planning strategy and tactics.

Life Safety First vs. Find and Fix

Your SOPs for gas leak emergencies should clearly indicate that life safety is the absolute overriding concern at these emergencies. However, as firefighters, we try to fix everything. In a video produced for the utility companies, Aegis, which insures many gas utilities, calls the temptation to try to fix everything the “find and fix syndrome.” Life safety always has to override “find and fix.” These excellent training videos are based on case histories that often resulted in deaths or injuries in various actual gas leak scenarios.7

The strategic goal of life safety first was highlighted in a case history from Teaneck, New Jersey. A man died when his house exploded and damaged five other homes on July 17, 2008. Many of the details remain unclear. In summary, it was reported that the utility had been called to the scene two weeks before and, again, on the day of the explosion and that the utility responder could not locate the leak source. The dead man’s relatives claim the utility never entered his home to check for gas migration. The utility denied this; it did settle the case for $450,000. It appears that the fire department was not involved here, but the lesson learned is that “life safety first” must be the policy and must be enforced on the scene.8

(2) The house exploded. This stretcher was to be Knapp’s ride to the trauma/burn center. Note the gas company trucks just beyond the stretcher.
(2) The house exploded. This stretcher was to be Knapp’s ride to the trauma/burn center. Note the gas company trucks just beyond the stretcher.

Firefighters, and sometimes gas technicians, tend to forget about life safety and focus on finding the leak or damaged pipe. Of course, if we can stop the leak, we can mitigate the life hazard. But, if we don’t evacuate endangered persons as our first priority and things don’t go well, we are not increasing the odds of survival for the occupants. Your policy, procedures, and training must be clear: life safety first, find and fix the leak second.

In the field, the motto “life safety first” causes several important actions and mindsets. First, it clearly sets our mission apart from that of the responding gas technician – for example, our life safety mission should lean more toward immediate evacuation and then shutting off the gas to a house or building. The gas technician does not want to be responsible for the cost of going back and relighting pilot lights and other appliances if he can isolate one single appliance in one single apartment. In his defense, he has been to a large number of gas leaks where nothing ever happens, just as we have.

Of course, the fire department’s first action at every odor of gas may not be widespread evacuation and shutting off the gas to an entire building, but the SOP must always allow these actions as options for the incident commander (IC) if at any time during the response the IC perceives lives may be in danger or the hazards of the situation are escalating.

Rapidly Assess

In 2013, in Kansas City, Missouri, firefighters responded to 911 calls of a strong natural gas odor and followed the lead of a Missouri Gas Energy worker and did not initiate an evacuation of the restaurant involved or nearby homes and businesses. An hour after those calls, the restaurant near the Country Club Plaza exploded, killing one person and injuring more than a dozen others. According to, “Missouri Gas Energy has settled a complaint alleging it failed to take adequate measures to ensure safety in a fatal 2013 blast caused by a gas leak at JJ’s Restaurant in Kansas City. The company, owned by the Laclede Group, agreed to change some of its emergency procedures and increase training in response to a 2014 complaint from the Missouri Public Service Commission’s staff.”

In the same article, it was reported: “Personnel from the Kansas City Fire Department responded to the initial gas leak report but left the scene before the explosion. The department has since changed its policy to have firefighters stay on the scene until any gas readings are in an acceptable range.” Then the department also changed its protocols.9

Another similar incident in which evacuations were not prompt occurred in Bergenfield, New Jersey, in 2005. In this case, the National Transportation Safety Board recommended that emergency responders “rapidly assess” gas leaks to determine if “prompt evacuations are warranted.” The agency said failure to evacuate contributed to the deaths of three occupants in the apartment at the time of the explosion.10

Many myths are associated with shutting off the gas to a home or business. We have heard some fire officers say that during the winter they do not want a home to freeze up if they shut off the gas supply. Even in the coldest climates, it will take a considerable amount of time for this to happen. If the gas leak cannot be resolved in that time, relocate the occupants and drain the water systems to protect the home. Life safety first!


Our research has shown that there is a huge difference between fire department and utility gas leak response procedures. We wondered why fire departments do not use procedures similar to those used by a gas technician from the utility. Fire officers and fire departments recognize the gas industry’s on-scene technician as the subject matter expert. Fire departments should be using response procedures similar to those used by the gas technician, especially if your department will get to the scene first and is responsible for the scene until the technician arrives.

Our informal survey of SOPs revealed that many fire department procedures are not proactive. One of the main weaknesses we have seen repeatedly in our review is that the SOPs are not procedurally based and do not follow the best practices of the gas industry, and they do not give the fire officer in charge a proven protocol and positive steps (procedure) to follow as a guide at gas emergencies – in the way that paramedics follow a specified set of protocols (procedure) that has been proven to provide the best outcome for a patient who has had a heart attack.

In New York, our Public Service Commission [aka Department of Public Service (DPS)] is responsible for regulating utilities. This regulating agency has a different name in different states. Gas company response procedures are public documents. The New York State DPS was a huge help in our obtaining valuable information. Similar agencies in other states have safety divisions and offer training oversight to ensure the utilities are providing the local responders with the necessary training. Partner with them. Compare your procedures with those of the gas companies, and contact your respective regulating agency.

Considerations When Revising Your SOP

You don’t want to go to every gas call the utility receives. Often, the gas technician arrives on scene (without fire department response) and finds a hazardous condition that meets threshold levels based on its protocols. The technician may then request the fire department. Approach this scene as you would a fire scene in which the fire alarm was delayed. In effect, you are arriving at a confirmed emergency, not a minor odor of gas. The gas may still be leaking, and the situation may be getting worse.

Fire Department of New York Battalion Chief (Ret.) Frank Montagna describes the gas technician as a “Lone Ranger” (not the cavalry) relative to the assistance given you. “When the utility representative arrives at your incident, he has a number of tasks to perform: make his own size-up, identify/evaluate the hazard, decide on a course of action, and determine if additional utility response is needed,” Montagna explains. “He will have to call his dispatcher, relay to him the present conditions, and request any additional help that he needs or that is an SOP mandate. Keep in mind that the response time of any additional help might be even longer than the utility’s initial response time.”11

(3) Note the size and the mass of the house framing blown across the street from this single-home explosion.
(3) Note the size and the mass of the house framing blown across the street from this single-home explosion.

Firefighters may feel overwhelming relief when the gas technician arrives on scene and often think that since the “expert” is here, we can now mitigate the incident quickly and safely. When we assume this, we are putting our complete trust and faith in this person; we are betting many lives on this technician, his instruments, and so on. We are betting that he is a competent and complete expert in procedures, gas detectors, sampling procedures, data analysis, communication with the fire department’s IC, emergency response, and so on. As in other vocations, every gas technician may not be the best and most experienced at what they do. Putting complete trust in them means you just bet the farm on them.

On October 16, 2016, a natural gas explosion in suburban Chicago injured two gas company employees (one was in fair condition and the other in critical condition) when two townhouses were destroyed. Details were under investigation, and 20 people were evacuated as a precaution.12 Gas technicians are human and make mistakes as we all do. They may or may not be well-trained, may be new on the job, may not be an expert in procedures, sometimes have a meter that is faulty or out of calibration, or may be having a bad day.

Joint Training

Joint training between utility workers and firefighters is critical to success on the scene. Leaders and members of both groups must train together as a team. Joint training will build mutual confidence, cooperation, respect, and full recognition of each other’s strengths and weaknesses. Joint, scenario-based training is a force multiplier that maximizes the effects of limited resources on both sides. Always keep in mind that our mission is” life safety first” and the mission of the utility is to make money for the stockholders and restore service to the customer as soon as possible.

Another way to help build safety and success when operating with your utility is to use a common radio frequency. Often, the gas technician finds a dangerous situation and requests the fire department. Think of the benefits the first IC would have if he could get a report directly from the gas technician! Since the gas technician is often working alone, this could be a vast improvement for his personal safety as well. We coordinate actions every day between truck and engine companies for obvious safety reasons. It is equally as important to coordinate operations at dangerous gas leaks.

Leak Classification by Hazard

Have you ever responded to the same location for the same smell of gas repeatedly? It is unrealistic to think that the gas-distribution system is completely leakproof except for the single leak to which you are called. Leaks of underground piping are classified by severity/hazard, and many exist in your area’s system. In very general terms, leaks are classified as grades 1-3; one is the most severe hazard.

  • Grade 1 leaks are a probable hazard to persons or property and require immediate repair and continuous action until the condition no longer exists. Actions include evacuation, blocking off an area, eliminating sources of ignition, and so on. Examples include any leak judged as an immediate hazard; ignited escaping gas; migration into a building; any leak that can be seen, felt, or heard; and readings above 80 percent LEL in a confined space.
  • Grade 2 leaks are recognized as nonhazardous at the time of detection, but they justify scheduled repairs based on the future probable hazard. Leaks should be repaired within one year but not more than 15 months later. Examples include leaks that require action before the ground freezes, any leak under frozen or other adverse soil conditions that would likely migrate toward a building, readings above 50 percent LEL under a sidewalk in a wall-to-wall paved area where it does not meet grade 1 criteria, any reading of 100 percent LEL or greater under a street with a wall-to-wall paved area, and many elevated gas readings in subsurface structures or confined spaces.

It is important to note that if a frost layer forms in the soil in the area of an underground leak during cold months, the frost layer could prevent the escape of leaking gas. Leaking gas, like water, will find the path of least resistance, which could be into nearby structures through cracks in the foundation, pipes, utility chases, and so on.

  • Grade 3 leaks are nonhazardous at the time of detection and can reasonably be expected to remain nonhazardous. Actions are reevaluated in the next survey or within 15 months of the date reported, whichever comes first. Examples include any reading less than 80 percent LEL in small gas-associated substructures, any reading under a street without wall-to-wall paving, and any reading of 20 percent LEL or less in a confined space.13

The above descriptions are generalizations and incomplete. The point here is that we repeatedly respond to numerous leaks that the utility knows about. The utility is required to maintain an up-to-date list of existing leaks. Have your dispatcher question the utility dispatcher about the details of the leak location. This will help you locate, size up, and more quickly mitigate the call. Of course, this information does not free you from running your SOPs for such a call. It is, however, vital information. Run your SOPs.


1. Clayton and Clayton 1981;

2. Managing Hazardous Material Incidents. Volume III. Agency for Toxic Substances and Disease Registry (ATSDR). 2001. Atlanta, GA: U.S. Department of Health and Human Services, Public Health Service.)


4. Guidance Manual for Operators of Small Natural Gas Systems, Pipeline and Hazardous Materials Safety Administration Chapter IV “Leak Detection.”

5. Fire

6. fire to natural-gas leaks, 3/6/2014.

7. Aegis training video, “Find and Fix Syndrome,” East Rutherford, NJ, 2008.

8. North, Nov 13, 2010.

9. Natgas Consultin, The AP, 03/12/2015; WWW.NATURALGAS WATCH.ORG, Mar 13, 2015.

10. Press release, NTSB.GOV/NEWS 5/1/2007.

11. Montagna, Frank. “Utility Response: What You Can Expect from Your Utility and What You Should Expect,” Fire Engineering, May 2015.

12., “Natural gas explosion injures 2 workers.”

13. For a complete description, go to Pipeline and Hazardous Materials Safety Administration Table 3A-C Leak classification and Action Criteria.

JERRY KNAPP is a 40-year firefighter/EMT with the West Haverstraw (NY) Fire Department and a training officer with the Rockland County Fire Training Center in Pomona, New York. He is chief of the hazmat team and a technical panel member for the Underwriters Laboratories research on interior and exterior fire attack at residential fires. He is the author of the Fire Attack chapter in Fire Engineering’s Handbook for Firefighter I and II and has written numerous articles for Fire Engineering.

DANIEL MORAN is a 45-year fire service veteran, a Rockland County (NY) deputy fire coordinator for hazardous materials, a member of the Rockland County (NY) Hazardous Materials Team, an instructor at the Rockland County (NY) Fire Training Center, and a former chief of the Suffern (NY) Fire Department. He has more than 40 years in the chemical-pharmaceutical industry as a research chemist. He has a bachelor’s degree in chemistry from Lebanon Valley College, Annville, Pennsylvania, and a master’s degree in chemistry from Fairleigh Dickinson University, Teaneck, New Jersey. He is an adjunct faculty member in the fire technology program of Rockland Community College (SUNY) in Suffern.

Jerry Knapp will present “Tactical Response to Natural Gas Leaks” at FDIC International in Indianapolis on Wednesday, April 26, 2017, 1:30 p.m.-3:15 p.m.


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