Law enforcement agencies are investigating a suspicious house fire that took place near the Mendenhall Campground on Friday morning, according to a Capital City Fire/Rescue statement.

At 1:34 a.m. Friday, CCFR responders went to a house fire in the 1100 block of Slim Williams Way, and found an attached home with a flames rising from the back of the house, according to a CCFR release. Responders quickly knocked the main fire down, but the blaze had extended to the attic space and firefighters had to pull up the ceiling sheetrock to fully extinguish the fire in the attic. The house was unoccupied at the time of the fire, Fire Marshals said, and one firefighter suffered a minor injury that did not require medical attention.

Crews were on scene for about two and a half hours, because the insulation was keeping embers smoldering, according to the release.

After an investigation, Fire Marshal Dan Jager put out a statement Friday morning saying the fire is suspicious. The blaze began in a back bedroom of the attached home, Jager’s investigation determined. The property is insured, and Jager estimated the damage at about $20,000.

This is the third suspicious fire in the Mendenhall Valley this summer, as there were two in one week in July. The Juneau Police Department is assisting CCFR in this investigation, and anyone with information is asked to call Jager at 586-0260.