A fire that destroyed an old building in downtown Sioux City over the weekend is being called suspicious. Sunday’s fire destroyed the historic Bekins Storage building, which was built in the 1890s and is now owned by State Steel.

It was vacant and no one was injured. A spokesperson for the Sioux City Fire Department says it appears someone got into the warehouse through a sliding fire door by kicking in a plywood wall that separates the old building from a newer section.

Investigators says a witness also reported seeing two teenagers taking pictures of the building the night before the fire.