A fourth floor lab fire forced an evacuation of Owens Science Hall Wednesday afternoon.

No one was hurt, but classes in OWS were canceled for the rest of the day. The building will re-open at 7 a.m. Thursday. St. Paul Fire District Chief Floyd Lecuyer said the fire started when an experiment ignited.

“There was a student working on an experiment,” Lecuyer said. “Somewhere along the line it was being heated and then the reaction took off so the vapors, we figure, came out and basically, possibly ignited.”

Lecuyer said that when the student tried to escape she knocked something over, which caused another small fire. Both fires were put out by the sprinkler system and Lecuyer thought water damage was contained to the lab area and some hallways.

Freshman Timon Higgins said he was in another lab when the fire started and that he and other students were sent to McCarthy Gymnasium after they were evacuated.

“Being a freshman, I thought it was a fire drill like in high school and elementary school, but I shortly realized that they don’t do fire drills in college,” Higgins said. “I grabbed my jacket, and we all came outside, and we were directed … to go across the street.”

Freshman Anne Dolan said she wasn’t sure what was happening when the alarm went off.

“We didn’t know if it was a drill or not at first, so we didn’t really know what was going on,” Dolan said.

Peter Gittens, a St. Thomas chemical hygiene officer, said students were being allowed back inside the building to retrieve their belongings because there was no longer any immediate danger from the fire.

Gittens said despite the lack of danger, classes will remain canceled for the evening.

“There’s no longer any immediate danger from the fire, but the building is not safe for academic use until they clear it further,” Gittens said.