Forest Hills, PA – A natural gas explosion and fire destroyed half of a duplex and shook a Forest Hills neighborhood like an earthquake Sunday afternoon.

Forest Hills Fire Chief Jim Theilacker said no one was at home on either side of the duplex at 322/​324 Avenue A when 324 exploded at about 1:40 p.m., blowing out the front windows, collapsing the roof and sending the back of the house toppling down and over a steep hill.

“It was a gas explosion. At least, we think so,” Chief Theilacker said. “The Allegheny County fire marshal will of course be doing a formal investigation.”

Jeff Phillis, who lives two houses away at 316 Avenue A, said he had just finished cutting his lawn and was on his front sidewalk when “the house just went boom and all the windows blew out into the street and brick facing flew off.”

Mr. Phillis said he called 911. The call came into the Allegheny County Emergency Dispatch Center at about 1:40 p.m. Dozens of firefighters and emergency responders were on scene within minutes, and a crowd of neighbors gathered as firefighters put out the fire. Representatives of Peoples Natural Gas company were testing the soil about 90 minutes after the incident occurred.

Michael Amorelli, 37, who lives two streets away on Avenue L, said he was in his kitchen overlooking Avenue A when he felt the explosion “like an earthquake or a bomb.”

He said he ran down the hill, knocked on the door at 322 to check if anyone was inside, but then had to back off because he smelled gas.

“Smoke was pouring out and I knew it was about to flare up,” Mr. Amorelli said. “Then it went whoosh and the flames just started coming out.”