Toxic Spill From Tank Car Causes Evacuation of Mile-Square Area

Toxic Spill From Tank Car Causes Evacuation of Mile-Square Area

Phosphorus trichloride fumes rise from accident scene in Somerville, Mass. ,At right is collecting pit for the toxic corrosive leaking from tank car against locomotive.

Boston Globe photo by Bob Dean

Deputy Chief’s Aide Somerville, Mass., Fire Department

A railroad switching yard minor collision resulted in the release of highly toxic and corrosive phosphorous trichloride and required the evacuation of a mile-square area in Somerville, Mass. With a population of 80,596 in only 4.9 square miles, the city has an average population density of 16,448 persons per square mile.

At 9:10 a.m. April 3, the fire alarm communications office received two calls from the Boston and Maine Railroad dispatch office, reporting that a diesel locomotive had crashed broadside into a tank car at the B&M switching yard at Joy and Washington Sts. A large toxic cloud was overhanging the area and B&M workers were fleeing.

The fire alarm office dispatched three engines, two ladder trucks and Deputy Chief John P. Brosnahan and also notified the local ambulance service to respond with two units. Engine 3 and Ladder 1, located at Union Square, only four blocks from the incident, reported off at 9:12 along with Brosnahan.

Fire alarm radioed that the B&M reported that the tank car contained about 13,500 gallons of phosphorus trichloride, a corrosive, toxic liquid. While this information was being received, members of Engine 1 and Ladder 1 were removing a B&M worker trapped by the toxic cloud.

Use of masks ordered

As more information about the chemical was being obtained from CHEMTREC by the fire alarm office, Brosnahan ordered all companies to wear full protective gear with masks. Companies were ordered to lay 2 1/2-inch hand lines, but not to charge them at this time. CHEMTREC reported that the chemical was water-reactive and that large amounts of water could be applied to the runoff—but not to the tank car.

Upon learning this, Brosnahan ordered a hole dug by B&M workers with front loaders to catch the spill running down the hill. B&M workers were given a crash course in the use of breathing equipment. However, not all of the spill flowed into the hole. Some was running down the hill to Joy St. and the sewer. The phosphorus trichloride was reacting with the damp ground and creating huge white toxic clouds in the area.

District Chief Willis Green, who responded to the Joy St. side of the spill with an engine and a ladder company, reported to Brosnahan by portable radio that the chemical was running down Joy St. toward the sewer. At this point, it was decided to open up the hand lines to dilute the runoff.

Evacuation necessary

Realizing that the water would intensify the toxic cloud, Brosnahan ordered the evacuation of an area of over 1 square mile, which included a Holiday Inn, a shopping center and several schools.

An engine and a ladder company were dispatched to the Holiday Inn to assist in the evacuation while police with loudspeakers evacuated the schools and homes.

After close examination of the tank car, Brosnahan knew there would be no chance of putting on any kind of patch to stop or even slow down the leak. The gash in the tanker was 3 feet high and 2 feet wide. After consulting with B&M officials and Chief of Department Charles Donovan, it was decided to bring in an empty tank truck to pump off the remaining chemical in the tank car.

Fumes shift with wind

Meanwhile the clouds of toxic fumes were shifting with the wind. The cities of Boston and Cambridge were notified of the potential danger heading their way.

As the morning drew on, fire fighters, along with scores of civilians, were taken to hospitals for treatment of skin irritations and inhalation of the toxic gas. The most seriously affected were the members of Engine 1 and myself. We had spent nearly all morning digging a trench to channel the phosphorus trichloride from the tank car leak to the hole being dug by front-end loaders. At various times throughout the morning, we were completely involved in the toxic cloud while digging the trench with hand tools. Every man in this operation exhausted over four tanks of air while digging. At 11:50 a.m., we were all taken to Somerville City Hospital by ambulance. The others were treated and released, but I was held 24 hours for treatment of first and second degree burns of both thighs, apparently caused by contact of the chemical and perspiration. I was on injury leave for 29 days.

Deck pipe is used by Somerville Wagon 2 in attempt to dissolve toxic cloud.

Photos by Ed Fowler

Chemical firm employee observes tank truck drafting phosphorus trichloride from pit.Locomotive remains at switch where it punctured tank car and caused chemical spill.

Chemical neutralized

As the day went on, various EPA, state and federal officials arrived. How to remove the more than 6000 gallons which were now in the hole was discussed. The civilians proposed a massive flooding with water. Brosnahan knew the effect this would have and argued against it. The deputy chief wanted as much of the liquid as possible pumped out into a tank truck and the balance covered with sand and soda ash. At first he was opposed by several EPA, state, federal and B&M officials, who had now ordered the evacuation of almost half the city.

After careful consideration, it was realized that Brosnahan’s proposal to use sand and ash was in fact the best idea and that operation was carried on throughout the night.

After he knew things were under control, Brosnahan, red-eyed and weary, went to the hospital for treatment. His expertise was a major factor in the control of the chemical spill.

All of Somerville’s seven engine and four ladder companies were at the scene throughout the day. All members who worked at the scene were given blood tests and chest X rays at Somerville City Hospital. A total of 45 officers and men were examined.

Two men still out

At the time this article was written, it was questionable whether two fire fighters will be able to return to duty because of damage to their lungs. Several others were being treated for liver problems and inhalation of phosphorous trichloride.

During this operation, 17 cities and towns sent self-contained breathing apparatus and cascade systems to Somerville. Along with Commissioner George Paul, the Boston Fire Department sent Rescue 1, a district chief, and the department’s chemist. All this assistance was handled by Metro-Fire, the 26-community mutual aid organization headquartered in Newton, 10 miles west of Somerville.

First-alarm apparatus was damaged by the fumes while directing fog streams from deck guns to try and control the vapor cloud spread. The wind shifted numerous times and apparatus was enveloped in the toxic cloud. The hose wagon of Engine 1 was placed out of service because the diesel engine was pitted by contact with the chemical fumes, and the Hurst Tool on Ladder 1 also had to be taken out of service because it also was pitted. The fumes also turned the lime yellow paint white on exposed apparatus.

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