Dozens of people were evacuated after fire broke out on the roof of a building that Yale-New Haven Hospital and Yale University use.
Fire alarms started going off at 9:11 a.m. after fire broke out at the building at the corner of Howard and Congress avenues.
The fire chief said the initial 911 calls came in as a fire at a factory building, but the fire was actually on the roof of a dual storage facility where medical experiments and simulations also take place.
Crews got the fire was under control in around 30 minutes.
The cause of the fire is under investigation, but officials said it appears it started near the air conditioning unit.