A commercial warehouse fire near NW 42nd St. and Leary Way NW sent a thick plume of smoke over Ballard and Fremont on Thursday evening.

100 firefighters rushed to the scene as a part of the building's roof collapsed.

The Seattle Fire Department escalated the blaze to three alarms, deploying Fireboat 1 from the Ship Canal to pump water to engines on shore, which then fed ladder trucks working the fire from the street. Crews evacuated the building and shifted to a defensive strategy, fighting the flames from outside rather than entering the structure.

One firefighter suffered a minor injury and was evaluated by an aid crew on scene, a Seattle Fire Department spokesperson told KOMO News.

Seattle police closed NW 42nd St. and Leary Way NW in both directions near 805 NW 42nd St. while crews worked. Fire officials urged residents in the surrounding blocks to close windows and doors because of heavy smoke.

The fire broke out adjacent to the Burke-Gilman Trail, the heavily used path connecting Ballard to Fremont and points east.

The department reported the fire under control later that night, but firefighters remained on scene for several hours monitoring for flare-ups. As of Friday morning, June 12, investigators were still on scene working to determine the cause. No damage estimate has been released.

Residents with information about the fire can contact the Seattle Fire Department's Fire Investigation Unit.