PITTSBURGH (AP) -- One person is in critical condition with burns after a unit in a Pittsburgh high-rise apartment building caught fire.

The fire was reported about 11:30 p.m. Thursday and was under control within an hour. But thick smoke prompted firefighters to evacuate the building. Those residents returned home about 2 a.m.

The fire was in an eighth-floor apartment. Various news reports say the building has either nine or 10 floors and The Associated Press has been unable to immediately reach officials who can confirm the building's size.

The cause of the fire is under investigation, but officials say it started in the living area of the apartment.

Officials have not released the name of the resident who is being treated at UPMC Mercy hospital.

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