ALLENTOWN, Pa. (AP) — Firefighters continue to battle an intense and smoky fire in a vacant warehouse that has been burning for several hours.

The fire in the former storage building in Allentown was reported around 6:30 p.m. Sunday. Hundreds of people watched as flames shot high in the sky and heavy, dark smoke billowed from the building's windows.

One firefighter was being treated at a hospital for burns to his hands, but no residents were injured. One nearby home was evacuated as a precaution, while several streets were shuttered for several hours.

It's not clear what sparked the fire in the four-story building.

The building had been slated for redevelopment as 60 apartments before the fire. The developer told The Morning Call of Allentown the building was frequently vandalized and entered by trespassers.