THE BRONX - A total of 54 families have been temporarily displaced after a four-alarm fire ripped through their apartment building early Wednesday morning.

Authorities blocked off the area outside 1055 Grand Concourse, where the fire began at around 4:20 a.m. Fire crews say the blaze began on the fifth floor and quickly spread to the roof, destroying five units on the top floor.

The fire marshal says the fire was caused by faulty electrical wiring in a space between the building's roof and ceiling.

Fire officials say three or four firefighters suffered minor injuries, and that one woman who lives in the building had trouble breathing. She is in stable condition at Jacobi Medical Center.

The Red Cross is on site helping the displaced families. News 12 is told that some of the families will be staying at a gym in Mullaly Park.