PHILADELPHIA _ The alarm sounded around 4 a.m. and the plant dispatcher began broadcasting across every channel at the sprawling Philadelphia Energy Solutions refinery in South Philadelphia. There was a leak. In Unit 433.
"As soon as they said Unit 433, we're coming out of our chairs," said an operator at the refinery who was working that shift. "That's the unit you don't want to leak."
The reason: 433 uses highly toxic hydrofluoric acid. A major accidental release could suddenly send a dangerous cloud of hydrogen fluoride drifting over South Philadelphia and other heavily populated neighborhoods.
"He was still transmitting the script when the first explosion rattled our blockhouse," recalled the operator, who asked not to be named. "You heard the tone of his voice change and he stumbled and then he changed it to a report of a fire, instead of a leak. It was like a fireball and there was smoke and vapor and horrendous noises and debris."
At 4:05 a.m., the Philadelphia Fire Department struck the first alarm.
That wouldn't be the only explosion at the refinery that morning.
In the end, it was the most serious refinery accident here in decades. The June 21 explosion and fire caused no deaths but had the potential to have been catastrophic. In a bitter irony, the only fatality to result from the fire appears to be that of the facility itself, which is now set for permanent closure. What follows is a reconstruction of that event as experienced by refinery workers on the scene that morning as well as firefighters and city officials charged with responding to it.
