PHOENIX TOLUENE TANK EXPLOSION
Rescuers in the Tower 5 incident were cognizant of the dangers posed by cutting into tanks containing residual toluene atmospheres. They remembered an incident in Phoenix, Arizona involving the ignition of toluene vapors within a steel tank during rescue operations.
In that incident of November 15, 1984, at the Western States Petroleum facility, a small petroleum bulk storage plant, firefighters attempted to rescue a trapped worker inside a 10,000-gallon, vertical, cone-roof tank. The worker was lowered into the tank to clean it. Breathing apparatus followed him down, but it was too late—he was overcome by residual toluene vapors within the tank soon after he reached the bottom.
In an effort to reach the victim quickly, the fire department attempted to breach the tank wall using a gasoline-driven power saw with a steel cutting blade. Working in relief shifts, responders made three cuts into the tank. Before the final cut was made, vapor ignition occurred inside the tank.
The primary impact of the explosion occurred at the point where firefighters were cutting the hole. The firefighter who was cutting at the time and his backup were thrown from their positions with intense force. The latter suffered massive head and internal injuries; he was killed instantly. Thirteen firefighters were injured; some had been thrown up to 10 feet beyond the area of operations. The injuries included burns, fractures, lacerations, and concussions. An autopsy determined that the worker they had attempted to rescue had died of asphyxiation/ toxic vapor inhalation 10 minutes after his entry into the tank.
For a complete report of this incident, see Fire Command, August 1985.