SALISBURY, N.C. (AP) — Eleven firefighters and two other people were injured in a house fire explosion in the Piedmont region of North Carolina, officials said.

Salisbury Fire Chief Bob Parnell said firefighters did not have life-threatening injuries but were getting treated for contusions, concussions and smoke inhalation following the fire Monday evening. Two other people were taken to the hospital, but Parnell said he didn’t know their conditions and couldn’t confirm whether they were in the house at the time of the fire.

The Salisbury Fire Department responded to the single-family home around 5 p.m. and found it engulfed in flames.

Eleven of the 22 firefighters at the scene went inside the house to search for occupants and “get water on that fire,” which preceded the explosion, Panell said at a news conference.

“It was enough force that the outside walls blew out, the roof came up and went back down,” Parnell said.

An investigation of the fire and explosion is continuing.