A Palo Alto home was completely gutted in what neighbors described as a massive gas-fueled explosion this morning.

The explosion was reported at about 8:29 a.m., and the house on the 400 block of Maureen Avenue was engulfed in flames by the time firefighters arrived a couple of minutes later, said Barbara Cimino, emergency manager for the Palo Alto Fire Department.

The male owner of the house was home at the time, but walked away with only cuts from glass. Other family members were not home.

The two-alarm fire was out by around 8:50 or 9 a.m., Cimino said.

David Bell, who lives a few houses away, said he heard “just an incredibly loud bang. I thought something must have fallen out of the sky and hit my house or something.”

He said he and another neighbor rushed to the house, looking for its occupants, and found the man in a side yard area, “completely stunned” but uninjured. They helped him climb the fence to a neighbor’s yard.

The roof had flown off sideways in the explosion, and partially landed on a neighbor’s house, Bell said.

One neighboring home was slightly damaged, while the home on the other side had only very slight damage to its exterior paint, said Palo Alto police Sgt. Dan Ryan. The home where the explosion occurred was a charred shell as firefighters continued to dampen down remaining hot spots at around 10 a.m.

“It was completely, completely engulfed,” Bell said. “It’s all gone,” adding that he and other neighbors believed it was a gas explosion.

Firefighters are investigating the official cause of the explosion and fire, Cimino said.