Residents of the Wood Street building in Wilkinsburg say the alarm went off about 6:30 p.m. Sunday when one resident burned some popcorn.
But the alarm, which features flashing strobe lights and a high-pitched screeching sound, has continued for more than 12 hours.
Allegheny County Housing Authority officials told a local television station that they're trying to locate the person who can shut off the alarm.
Residents say they've been robbed of a night's sleep - but also of the peace of mind that they'd be alerted if a real fire occurred in the meantime.
