SEATTLE >> The Seattle Fire Department says an explosion linked to the production of marijuana extracts blew a one-story building off its foundation, but didn’t cause any injuries.

The blast Tuesday afternoon occurred after canisters of butane that had been stored in the freezer of a vacant apartment unit leaked into the refrigerator’s electrical components. Spokesman Kyle Moore says the butane was for use as a solvent in making hash oil.

The explosion blew off the kitchen cabinets, blasted a hole in the ceiling and knocked a wall of the building 6 inches off its foundation.

The building has a flower shop and three vacant apartments. The flower shop owner was inside.

Police responded and found what spokeswoman Renee Witt described as a "sizeable" marijuana growing operation.

On Jan. 1 an explosion linked to hash oil production damaged two Kirkland apartments, and similar explosions injured people in Spokane and Mount Vernon last summer.

Butane is extremely flammable. In gas form it can accumulate in poorly ventilated areas, where even a spark can cause it to explode.