MARYVILLE, Mo. -- Two people died Wednesday night in a powerful explosion that leveled their home in the northwest Missouri community of Maryville. A third person who survived the blast was hospitalized with severe burns.

Fire inspectors believe the blast came from a natural gas leak in the home.

Lois Hall, 93, and her son, Carroll, 69, were killed in the explosion, said Keith Wood, Maryville public safety director.

"They were sitting in the living room and the house blew up," said Mike Carlson, a relative of the victims.

Wood said another son, Donald, 49, who also lived in the home, was taken first to a local hospital, then flown to the University of Kansas Hospital in Kansas City, Kan.

The explosion was reported just before 9 p.m. in an older neighborhood near the Northwest Missouri State University campus. Neighbors found the youngest Hall crawling out from under the debris.

Wood had described his injuries as "very serious" and said he was "in and out of consciousness" before being taken from the scene.

Wood said the Hall house had a natural gas furnace and hot water heater. The survivor spoke of having smelled gas earlier in the day, he said.

The explosion was heard and felt in a widespread area, with some people saying at first they thought there had been an earthquake.

Chad Waller, sports information director at Northwest Missouri State, said the explosion was felt in the school gym during a basketball game.

"I felt it shake," he said. "It rattled for a second or two. I thought it was a tremor, like an earthquake tremor."

"All of a sudden there was a giant explosion -- everything vibrated," witness Linda Baker said. "We went out in the front yard and there was this mushroom cloud."

"I ran to the window and just saw a fireball," said one area resident, Laura Widmer.

"Stuff you see on TV, you don't realize you're going to be in the middle of it ... It's amazing someone lived through it," Carlson said.

KMBC's Dan Weinbaum reported that the street and surrounding yards were littered with debris. Neighbors salvaged what they could to return to Hall's family.

"I think the pictures will be real important to get," Carlson said.