Pittsburgh Bureau of Fire and EMS responded to a report of a duplex fire on the 600 block of Bigelow Street around 3:20 a.m.

Firefighters observed flames on the upper level of the structure. It started as a 2-alarm fire upon the responding crew’s arrival. It was later escalated to a 4-alarm fire.

One female was able to escape on her own from an adjacent unit. She was transported to Mercy hospital by medics for smoke inhalation.  A male of the burning unit exited the home on his own and transported by medics in serious condition. A third female victim was located on the second floor. Firefighters extricated the victim where medics pronounced her deceased.

Two firefighters were checked by medics for dizziness.

Firefighters were able to extinguish the fire after an hour and a half.

The Fire Investigation Unit, comprised of Pittsburgh Police detectives and Pittsburgh Fire investigators, is investigating the cause of the fire.