NEW YORK (CBSNewYork) — Firefighters are still on the scene of a four-alarm fire that broke out early Thursday morning in Brooklyn.

The fire is believed to have started around 5:15 a.m. in a hardware store at the ground level of a four-story building on Fulton Street in Bedford-Stuyvesant.

When crews first arrived, the FDNY said they were met with heavy fire and said the store was fully engulfed in flames. Video from the scene showed smoke and flames pouring from the building as firefighters worked to get better access to the blaze.

Fire officials said the second floor collapsed onto the first. The FDNY said on Twitter that there will be an “extensive operation to get pockets of fire extinguished.”

The FDNY said one firefighter suffered a non-life threatening injury. No one else was hurt.

The exact cause of the fire in unclear.

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