A South Hall family continues to recover in hospitals after their home exploded early Friday morning.

Dan Johnson and his wife Susan Johnson were trapped beneath rubble for more than half an hour as emergency crews used chainsaws to free the couple, according to Capt. Scott Cagle, Hall County fire marshal.

Their adult son, Michael Allen Clack, was also pinned down by debris but was quickly freed by neighbor Jim Wingo.

Dan Johnson's status is listed as "satisfactory" at the Northeast Georgia Medical Center, Michael Allen Clack is said to be in "good" condition at the Joseph M. Still Burn Center in Augusta and Susan Johnson is being treated by the Atlanta Medical Center's Intensive Care Unit.

A family member confirmed Friday everyone is expected to be OK.

The explosion shook the upscale neighborhood on Blackberry Lane in Buford around 5:30 a.m., according to neighbors.

"The noise — I've never heard a noise like that. One big boom," next-door neighbor Nancy Karr said Friday. "I grabbed my husband and started screaming. I thought, ‘Oh my God, the end of the world is coming.'"

Wingo said the blast blew open several of his home's doors in the middle of the night.

"I could hear (Clack) over there calling for help," he said.

"He was lying on his side and had a piece of interior wall on him. I was able to lift that up enough for him to pull himself out."

However, Wingo said the Johnsons, who slept on the middle floor, were trapped in the house. He could hear Dan Johnson yelling beneath the rubble, but wasn't able to get to them.

"(Clack) wanted to help his mom and step-dad," he said. "I told him there wasn't much I could do.

"I couldn't see them. They were completely covered with debris, but the father could see my flashlight shining. I could hear him but I couldn't understand what he was saying. ... I couldn't hear the mother, but Dan said he could hear her and was talking to her."

Emergency crews responded at 5:58 a.m. and began digging the couple out, according to Cagle.

Neighbors say both Dan and Susan Johnson sustained broken bones but were conscious when they were freed about half an hour later.

Clack, who lived in the basement, suffered "flash burns," Cagle said.

The cause of the explosion has yet to be determined, but Cagle said it appears to be a gas leak incident.

A 120-gallon liquid petroleum tank is one possible cause, but Cagle said every gas line and appliance will be examined.

The tank was intact but leaking when first responders arrived Friday.

"(It) can still be intact if there was a leak in the line," Cagle said.

"So if there was a leak in the line and all the gas leaked into the house, any ignition source could have done it. A telephone, AC unit kicking on, a ceiling fan, something like that. It's common for the tank to still look like it's OK."

The home was valued at $746,475, according to Hall County property tax information.