Firefighters this morning reported they had contained a three-alarm blaze at a South San Jose storage facility, which was still smoldering at dawn.

The fire was reported at a Public Storage facility at Blossom Hill and Cottle Roads shortly after 6pm Wednesday, fire officials said.

Crews heard explosions coming from the fire, which was quickly upgraded from two to three alarms Wednesday evening. The fire is located across the street from a fire station and from Westridge Oakridge Mall.

Towering black smoke could be seen for miles in the clear evening sky.

Roads are closed in the area and traffic is delayed.

Firefighters worked overnight putting out hotspots and preventing flare-ups. There were no reports of injuries as of early Thursday morning.

The cause of the fire was not immediately known.