Updated

SUFFIELD, Ohio -- A home exploded into flames early Wednesday, killing a woman and her grandson and throwing them from the house in a blast that was heard miles away and left nothing at the site but a large crater filled with debris.

As firefighters doused the smoking wreckage, the victims' relatives walked through the debris in shock. Killed in the explosion were Regina Proudfoot, 63, and Robert Croft, 21, said Portage County Sheriff David Doak. No one else was injured.

Next-door neighbor Mike Baughman said he thought there was "an airplane crash in the backyard."

"We ran to the windows and saw Regina's place on fire," he said. "And then about a minute later there was a subsequent explosion."

Investigators have confirmed the explosion was related to a propane tank in the home, but the cause is still under investigation, state fire marshal's spokesman Shane Cartmill said.

The bodies of Proudfoot and Croft were found next to the home, and debris was spread for more than 1,000 yards, Doak said. Several other homes were damaged, including a neighboring house left uninhabitable, he said.

The booming blast, at about 4 a.m., was heard several miles away by Suffield Township Fire Chief Bob Rasnick.

"We could only get so close because of the amount of debris," Rasnick said. "We found a ball of fire from the gas that was still feeding the fire. The family lives right next door, and they told us that there were two people inside the house."

In a 911 call, a neighbor is heard saying, "Please hurry. ... A house just blew up. ... A house just blew up, in the back, propane. There's people in there."

Another caller describes a "massive explosion."

"I mean, it shook the whole house," she says. "I don't know where it's at. I don't see a fire or anything."

Proudfoot's daughter, who lives next door, was screaming that her relatives were inside, Baughman said.

"A lot of screaming and just a lot of devastation for that family," he said. "It was sad because the husband passed away building that house a year ago from a heart attack in the basement."