"It's hot, I see fires. I said, 'I got to get out of here,'" Sommerville said, recalling that night.
As the natural gas whistled in the cold night air Tuesday, Kevin Sommerville was on the second floor of the now destroyed building.
The blast plunged him two floors into the basement where he finally awoke in the rubble.
"I just remember spitting rocks, spitting plaster, I was spitting stuff out," he said. "I remember duct work being in my way. I got past the piece of duct work and I remember - wide open, the house was wide open."
Sommerville suffered second degree burns on his hands and face. Doctors had to put 12 staples in his head to close a gash. But he says his physical injuries will heal.
It's the emotional one that will be tougher to overcome.
19-year-old Mark Keeley died in the explosion. He'd only been on the job less than a year and his father, Tom, is a longtime coworker of PGW.
"Mark's the baby. Mark's 19. I was keeping an eye on him. I thought he was in a good spot. Aw man. I feel bad. I wish it didn't happen," Sommerville said.
Sommerville says Keeley was drilling ventilation holes in the ground outside when the natural gas ignited. Sommerville was in the building evaluating the extent of the gas leak and desperately trying to learn if anyone was inside.
"We drill holes in the ground to find leaks. You ventilate, you drill holes, you ventilate, you pinpoint the leak. I see him with the drill getting ready to drill holes and I said 'it's a good job for Mark,'" Sommerville said. "Another 5 more minutes, another 2 more minutes, another 10 more minutes, things may have been different."
While Mark Keeley's infectious smile continues to keep him awake at night, he says Mark's father has helped him deal with the inherent guilt in the wake of the tragedy.
"He told me to get myself better. They're very gracious and I thank them for that," Sommerville said.
Two other coworkers suffered serious burns in the blast. Kevin Sommerville says they've also been released from the hospital.
The Fire Marshal's office continues to investigate the cause.