NEWPORT – Donald Lamson’s neighbors heard an explosion Thursday morning, ran outside to see what happened, then pulled Lamson away from his burning summer home on Sebasticook Lake.

A liquid propane gas leak inside the two-story Cape Cod-style house was the source of the explosion, but what sparked the explosion was still unknown late Thursday, said Stephen McCausland, spokesman for the state Department of Public Safety.

Lamson, 73, was taken to Sebasticook Valley Hospital in Pittsfield, then flown to Eastern Maine Medical Center in Bangor.

The hospital had no information on Lamson on Thursday afternoon.

His injuries were not considered life-threatening, McCausland said. “We’ll wait until his medical condition improves before we talk with him,” he said.

Frank and Kathy Pray, who live next door to Lamson on the lake, heard the explosion around 7:30 a.m. and swiftly moved their neighbor from just inside the doorway of the home.

Lamson is a summer resident with two homes on Kitchen Hill Road, the cape and a smaller camp.

Firefighters from Newport, Pittsfield and Corinna went to the scene, said Newport Fire Chief Fred Hickey. He said the first units found the home engulfed in flames.

Another neighbor, who lives within sight of the fire, said his camp shook from the explosion.

“Frank Pray and his wife had moved him by the time I showed up,” said the neighbor, who asked not to be identified. “He was just dead weight.”

Charred wood, wire and appliances were all that remained of the home, which was heated by gas. A shed on the lakefront and his camp next door remained intact.

Lamson, who lives in Westbrook, Conn., has been staying at Sebasticook Lake for most of the summer.

McCausland said the actions of Lamson’s neighbors are typical. “That’s what neighbors are for,” he said.