A Newark firefighter rescued himself by climbing out of a third-floor window during a late-night fire that tore through two buildings in Newark Thursday, officials say.

According to Newark Public Safety Director Emanuel Miranda, firefighters were called to 477 North 6th St. just after 10 p.m. for a report of a fire in a three-story apartment building. Officials say the fire spread quickly, extending to an adjacent building at 479 North 6th St. and reaching two alarms.

As crews worked to knock down the flames, one of the firefighters working on the third floor of the building was forced to transit a mayday call for help, according to Miranda. Crews immediately extended a ladder to assist him.

"The firefighter self-rescued after a ladder was extended to the third-floor window where he had sought refuge. He was treated at the scene by EMS and remained on duty," Miranda said.

There were no other injuries reported and the fire was brought under control just after 11 p.m., officials said.

Newark police say five families, comprised of 13 adults and six children, were displaced by the fire. New Jersey Red Cross teams responded to assist the families.

Miranda said the cause of the fire was not immediately known. He said it is being investigated by the Department of Public Safety’s Arson Unit.