MIAMI -

Firefighters worked for hours to extinguish a massive fire at a two-story commercial property Friday night in Miami.

Costumers were washing and drying their clothes at J&J Coin Laundry, 2322 Northwest Seventh Street, when they reported smoke.

Witnesses told firefighters the flames moved quickly through the building.

About 40 firefighters responded and struggled with an unstable roof, Miami Fire-Rescue Lt. Ignatius Carroll said.

No one was injured, and the cause of the fire remains under investigation, Carroll said.