What caused a camper to catch fire in Hartford Township on Thursday morning remains under investigation.

Firefighters arrived at the scene on Brockway Sharon Road at around 5:40 a.m.

Fire officials believe it started in a camper trailer and spread to the roof of a nearby detached garage.

A passerby spotted the flames and called 911.

“They stopped and knocked on the door of the house to make sure no one was inside, and they proceeded to call 911 on their cell phone,” said Brookfield Twp. Fire Chief David Masirovits. 

The camper was destroyed in the fire.

The State Fire Marshal’s Office is investigating to determine what started the fire.