A fire that tore through the roof of the Plymouth Village Condo Complex in Central Islip forced residents to run from their homes in the middle of the night.
Fire officials say the fire started around 12:30 a.m. on Adams Road. In all, 21 people were displaced.
Investigators from Suffolk County's Arson Squad spent the morning combing through the apartment where the fire began, trying to figure out what started the blaze.
The American Red Cross made sure the displaced residents have a place to go.
Officials say no one was hurt during the fire.