The National Transportation Safety Board (NTSB) Tuesday cited the inaction of Public Service Electric and Gas Co. (PSEG) as the "probable cause" of an explosion and fire on a natural gas distribution line in Bergenfield, NJ, that caused three fatalities, injured five persons and destroyed an apartment building in December 2005.

PSEG failed to conduct effective oversight of the excavation of a fuel tank and was not prepared to promptly shut off the flow of the gas after its service line was damaged during the incident, the NTSB concluded. In addition, the board found that the Bergenfield Fire Department's failure to evacuate the apartment building, despite the strong evidence of a gas leak, contributed to the casualties.

"Excavation damage continues to be a significant cause of dangerous gas pipeline explosions," said NTSB Chairman Mark V. Rosenker. "There is a need for greater vigilance in preventing these accidents, and for increased emphasis on training service workers and first responders to deal with these emergencies when they unfortunately do occur."

Investigators found a break in a 1 1/4-inch service line at an underground connection downstream from where excavators were removing a 5,000-gallon fuel oil tank that was buried under an asphalt parking lot adjacent to the apartment building. Workers told investigators that the ground surrounding and supporting the pipeline had collapsed. This caused the damage to the service line and the migration of natural gas into the nearby apartment building, according to the NTSB.

As a result of its investigation, the NTSB urged PSEG to revise its excavation damage prevention program and emergency plan to require site-specific risk assessments of excavators' plans, and to implement procedures to effectively mange the risk, such as increased surveillance of excavator actions to protect the pipeline and ensuring that gas shutoff valves are tested so that they can be closed promptly if a pipeline is damaged.

Moreover, the board called on the International Association of Fire Chiefs to notify its members of the circumstances surrounding the Dec. 13, 2005 accident in Bergenfield, and urge them to establish and implement procedures for emergency responders to rapidly assess situations involving natural gas leaks and to determine whether prompt evacuations are warranted.

PSEG is the largest provider of natural gas and electricity in New Jersey, servicing 1.7 million gas customers and 2.1 million electric customers in more than 300 communities, including the state's six largest cities.

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