A person was critically injured in an apartment fire in Longwood early Sunday morning, according to the FDNY.

Firefighters responded to 540 Southern Blvd. around 6:20 a.m. for a fire in a fourth-floor apartment.

The FDNY says 21 units and 79 fire and EMS personnel responded to the scene.

Fire officials say the person who suffered serious injuries was taken to a local hospital.

The fire was placed under control at about 7:26 a.m.

The cause of the fire is under investigation.