Cramblett Hall, the medical clinic building at the Ohio State University Medical Center, was evacuated Tuesday afternoon because of a report of a natural gas odor in the building.

At 1:50 p.m., security at the medical center reported a strong odor of gas to the OSU police department, Deputy Chief Richard Morman said.

Morman said that, according to the report, the gas came from the pedestrian tunnels under the building, and the building was quickly evacuated so the source could be investigated.

Alyssa Sims, an employee at Cramblett, said they were told to evacuate all staff and patients at about 2 p.m.

Battalion Chief Michael Fowler of the Columbus Division of Fire said a generator was the source of the gas. Fowler said employees were performing routine maintenance on a generator, and it emitted odor into the building.

“They ran a test on the machine, and it put fumes in the building,” Fowler said.

David Crawford, a director of communications and marketing at the OSUMC, said someone in the building confused exhaust fumes from the generator as a natural gas leak.

At about 2:25 p.m., firefighters and other emergency response teams left the scene and people re-entered the building after the source of the odor was identified, contained and considered non-threatening.

David Gerad contributed to this story.