Butler Township fire crews are investigating the cause of a fire that destroyed a house on Germaine Road early Saturday morning.

The incident occurred at 129 Germaine Road, Butler Township, at 6:06 a.m.

Four residents of the home were transported to the hospital by Butler Ambulance Services, with one being flown to West Penn Hospital in Pittsburgh for burns. The other three residents are being treated at local hospitals for injuries suffered in the blaze, according to Butler Township Fire Marshall Larry Christy.

Christy said the first arriving crews found a fully-involved residential structure fire, with heavy flames in the basement of the home that had moved into the first floor, the rear of the structure and into the attached garage.

The flames led to a roof collapse in the home, he said.

Crews will remain on scene much of Saturday putting out hot spots before an investigation into the cause can be conducted, Christy said.

A preliminary statements that the cause could have been a malfunctioning kerosene heater were reported, but Christy said a cause has yet to be officially determined.

Butler Township Station 3 and 7, as well as Unionville Fire Department, Butler Ambulance Service and the Red Cross assisted at the scene.