WEST CHESTER, Ohio (AP) — A fire at a mobile home park in Ohio claimed the lives of three people and sent a firefighter to a hospital for treatment, authorities said.

A local police officer spotted smoke and located the blaze at the Princeton Crossing mobile home park in West Chester Township at about 12:30 a.m. Tuesday, fire officials said.

Firefighters pulled three adults from the home, treating all with CPR at the scene and taking two of them to UC Health West Chester Hospital and the third to Mercy Hospital.

Fire Chief Rick Prinz said all three were pronounced dead after they were taken from the scene. Their names weren’t immediately released. One firefighter was taken to the hospital for treatment of heat exhaustion.

Most of the fire was in the back bedroom of the home, and the roof and a part of one wall collapsed, officials said.

The cause of the blaze is under investigation by a state fire marshal.