A man was critically injured Monday when a natural-gas explosion destroyed a room at a motel in North Seattle, according to the Seattle Fire Department.

Police and firefighters responded to the Klose-In Motel, at 9309 Aurora Ave. N., just before 11:30 a.m. after the blast blew out a wall of a room, said Kyle Moore, a spokesman for the Seattle Fire Department.

The victim, a man in his 40s, was taken to Harborview Medical Center in critical condition after being burned in the explosion. Residents of the motel said the man was blown out of his unit and was found rolling around in pain.

“I couldn’t believe he was alive,” said Michelle Dupree, who was asleep when she heard a “huge boom that sounded like a truck hitting something.”

When she opened the door, police were telling people to evacuate.

“They said it wasn’t safe,” she said.

Resident Rick Machado also was asleep when the blast rocked the motel. He said the victim’s next-door neighbor thought it sounded “like a plane crashing” into the building.

The front wall of the damaged room was blown out by the blast, and the interior was a jumble of wreckage. The roof over the unit appears to have buckled.

The motel was evacuated as firefighters assessed the building’s structural integrity, Moore said. Gas and power were turned off.

The Red Cross is helping the 41 people displaced by the explosion.

Investigators said the accidental blast was caused by natural gas.

Damage to the building and contents was estimated at $55,000.

Christine Clarridge can be reached at 206-464-8983 or cclarridge@seattletimes.com