MINNEAPOLIS (WCCO) – A leaking natural gas pipe was the cause of a Northeast Minneapolis house fire that left two families displaced, one person injured and five firefighters with heat exhaustion Sunday afternoon, authorities said.

The Minneapolis Fire Department said the fire, which burned inside a house on 2321 Fillmore St. NE, started around the home’s furnace. The gas leak caused an explosion shortly before 3 p.m. and filled three floors with flames. The blast also pushed out a section of the exterior wall in the back of the home.

The department said the injured resident is still in the hospital, recovering from his injuries. His name was not released.

The five firefighters who were transported to the Hennepin County Medical Center for possible heat exhaustion were released late that night.

The fire displaced four adults and two children. The American Red Cross is assisting them.