Police say gunfire broke out at a private club in the city's Larimer neighborhood just after 3 a.m. Sunday.
Responding officers found a man with a gunshot wound to the back. He was pronounced dead at the scene. His name was not released.
Another man was taken to UPMC Presbyterian and listed in critical condition. No arrests have been reported.
In suburban Pittsburgh, authorities said a teenager was shot to death late Saturday in a Wilkinsburg park.
The Allegheny County medical examiner's office says the 17-year-old victim was pronounced dead in the Hunter Park section of the borough at 10:32 p.m. Saturday. No arrests were reported.