Fire alarms went off around 11:45 p.m. Wednesday inside the Constans Theatre on campus.
Five Gainesville Fire Rescue trucks and University Police Department officers reported to the scene shortly after midnight.
Steam was seen billowing from the building, but fire rescue Lt. Ken Johnson said there was no fire and that the steam was coming from the boiler room. The incident is still under investigation, but no injuries have been reported.
Johnson said the fire rescue had received several calls reporting the steam.
Takashi Morimoto, a UF graduate student who had been working backstage at the building Wednesday night, was inside its costume shop when the sirens went off.
He left all his belongings, including books and car keys, inside the room and walked outside.
"When I got out of the building I kind of smelled smoke or something weird, but it wasn't strong," Morimoto said.
When UPD arrived, Morimoto led two officers inside the theater because the building's layout can be confusing, he said.
Fire rescue reported to the first floor of the building, where the boiler room is located.
Steam had filled the room enough to max out pressure gauges, which created too much heat for anyone to be near the room, Johnson said.
Johnson said fire rescue officials were afraid the windows of the building might be blown out from the pressure.
As a precaution, fire trucks were moved away from the theater building.
A Regional Transit System representative, who declined to give his name, said buses scheduled to travel through McCarty Drive were rerouted at 12:25 a.m.
Buses used Center Drive as an alternate route.
At 1:20 a.m., fire rescue officials were waiting on a UF maintenance employee to help determine what should be done.
Alligator Staff Photographer Nicole Safker contributed to this report.