Philadelphia Refinery Fire Out, Probe into Cause of Blaze to Begin

A fire in a Philadelphia refinery struck by explosions and a pre-dawn blaze last week has now been extinguished as an investigation is launched into what caused it, authorities said.

The blaze at the Philadelphia Energy Solutions Refining Complex, the East Coast’s largest oil refinery, was extinguished Saturday afternoon, fire department and city officials said in a statement Sunday. The gas valve that had been fueling the blaze had been shut off and the tank involved in the explosion had been isolated, officials said.

The fire department’s hazmat unit and the public health department are still monitoring air quality, which they said earlier they have been doing every two or three hours without finding any threat to public health.

The blasts and fire at the plant at about 4 a.m. Friday, which shook homes and sent a fireball aloft, occurred at a tank containing a mixture of butane and propane, authorities said. Five workers were treated for minor injuries, and nearby residents were asked to stay inside.

Starting Monday, the cause and origin of the fire will be investigated by the Occupational Safety and Health Administration, the Bureau of Alcohol, Tobacco, Firearms and Explosives, the U.S. Chemical Safety and Hazard Investigation Board and the fire marshal’s office, officials said.