RAPID CITY, S.D. (KELO) — Investigators in Rapid City are looking into what sparked a fire in the northwestern part of the city last week.

Authorities say it happened in the 3600 block of Deadwood Avenue North just before 2 a.m.Thursday.

Crews arriving on the scene found smoke coming from a large commercial building.

The Rapid City Fire Department shared this first-person view of the fire.

You can see firefighters forcing the door open before spraying water on the blaze.

No injuries were reported.