The fire broke out on the third floor of the facility at 525 North Garfield Avenue at about 6:40 a.m. Firefighters evacuated the third and fourth floors because of the smoke.
There were no reports of any injuries, and it's not clear what sparked the fire.
The 98 patients on those floors were moved to the bottom floor of the hospital, which was not affected. Hospital staff transferred many of the patients to other facilities.