The victims, a husband and wife, were both taken to Crozer Chester Medical Center in critical condition.
"It definitely was an explosion," Township Manager Michael Voll tells Action News.
The blast reverberated through Lower Township around 4:00 p.m. creating a debris field down the 200 block of Atlantic Avenue in the Villas community.
Lower Township Mayor Michael Beck tells Action News he was at home, less than 100 yards away from the scene, when he heard the explosion.
"It was hard to describe. It was certainly a lot more loud than thunder," Beck said.
"It was like BOOOOOOM, and shook our whole house," said Antoine Sloane.
The mayor said he along with neighbors ran toward the house.
"Kudos to the neighbors because they had two people trapped in there, two seniors, and the neighbors pitched in and went in there and pulled these people out," Beck said.
"I can't even explain it. It felt like an earthquake, and I went running out and the whole side of the house was blown across the yard," said Nick Plasi.
Nick Plasi and a half dozen other neighbors, including an off-duty officer, rushed explosion site where they found Jim and Evelyn McCarty stunned, bloody and burnt.
"The lady was real banged up. Her ankles were twisted and looked real bad. I helped carry her out and another gentleman," said Antoine Sloane.
"Jim was in the shower at the time. That whole wall was blown out, and he came stumbling out of the wall, and we got him out and it just went up in flames," said Plasi.
"If they hadn't got these people out of there, I have no doubt they would have been in serious trouble," Beck said.
Firefighter quickly responded and worked to extinguish the fire while the two vicitms were driven to a nearby airport and flown to Crozer Chester Medical Center's burn unit.
"The guy was burnt real badly; his chest hair looked like it was stuck to his skin, his facial hair was burned, the hair was browned and singed," said Sloane.
"Jim said to me when we were walking that he smelled the gas," said Plasi.
New gas lines were just installed in the neighborhood, but officials say it is too early to determine the cause.
"We are still looking into that," said Mayor Michael Beck. I'm sure it's just process to take their time with that. I don't want to speculate at this point."
Mayor Beck says the house is totally demolished.
Police say the fire went to a second alarm before it was placed under control.
Homes on the street were evacuated for around an hour as a precaution.
ATF agents and the county fire marshal's office are handling the investigation.
The two victims remain in critical condition.