Seattle fire investigators have determined the cause of a three-alarm fire that broke out at an apartment complex in North Seattle Saturday.

Faulty electrical equipment sparked the fire in a kitchen on the second floor of the building.

The fire broke out at a three-story building at Meridian Avenue N and N 113th Street around 2:20 p.m. The fire created a giant plume of black smoke visible from miles away.

Firefighters said they tackled the fire defensively from the outside and brought in a King County Strike Team to assist with putting out the flames. At the height of the fire, there were 13 engine companies and nine ladder trucks at the scene.

One firefighter was transported to Harborview Medical Center for minor injuries.

No tenants were inside the building during the fire, and no injuries were reported.

Thirty apartment units were impacted by the fire. The Red Cross was helping about 60-70 residents who were displaced.

Investigators estimate the fire caused $6 million in damage; $4 million in structural damage and $2 million to contents.