Firefighters with the Pittsburgh Bureau of Fire responded to the 7900 block of Madiera Street for a 2-alarm residential structure fire at 11:25 p.m.

Once on scene, firefighters observed heavy flames coming from the second floor of the structure, which was unoccupied. The fire grew to three alarms.

While fighting the blaze a firefighter fell about 10 feet off of a ladder and suffered a laceration to his head. He was conscious and alert while medics treated him at the scene before he was transported to the hospital.  A second firefighter twisted his back after falling through a hole in the floor. He was evaluated by medics at the scene and transported to the hospital for further evaluation. A third firefighter was treated at the scene for symptoms of extreme heat exposure.

The fire was declared under control just before 12:25 a.m.

The Fire Investigation Unit is investigating the cause of the fire.