A fire that began today at around 2 p.m. in Montefiore Medical Center’s main building on Gun Hill Road forced the evacuation of 250 hospital employees for a little more than an hour. Montefiore officials said no one was injured, patients were temporarily transported to other parts of the building and employees successfully followed emergency procedures.

After carbon dioxide levels died down, employees returned to work shortly after 3 p.m.

Witnesses said black smoke began billowing out of a Montefiore building vent on Gun Hill Road, near Baibridge Avenue, at around 2 p.m. Soon, Montefiore employees were streaming out of the front entrance to the building wondering when they would be allowed to return.

The two-alarm fire completely shut down traffic around the already congested intersection of Bainbridge Avenue and Gun Hill Road.

Inspector Joseph Dowling, the commander of the 52nd Precinct, said the fire erupted in the boiler room, but was mostly doused by “foam units” that dispersed automatically when the fire started. Smoke from the fire began circulating through the hospital’s ventilation system causing conditions that forced an evacuation of patients and staff.

Patients being treated in the emergency and intensive care units were taken to other parts of the building that weren’t affected by the fire, a Montefiore spokesperson said.

Meanwhile, in the hospital’s operating room, business continued as usual. David Turk, an anesthesiologist who was in the middle of helping out with a thyroid operation at the time the fire broke out, said they could smell smoke and knew something was happening, but it didn’t affect their case.