The Lattie F. Coor Building was evacuated Thursday after a steam-release valve triggered the building's fire alarm.
The alarm sounded at approximately 10:30 a.m. Students and faculty were allowed to re-enter the structure an hour later, when Tempe firefighters and ASU personnel determined there was no danger.
"A pressure-release valve on the steam line opened and released steam," said Dave Brixen, director of Facilities Management for the University. "It functioned properly. The system was overpressurized."
Brixen said the incident warranted an investigation because a steam release on a structure as new as the Coor building is rare.
"We don't know what caused the overpressurization, and we're looking into that," he said.
Justice studies senior Nicole Bankert was among the hundreds of people who evacuated the premises as Tempe firefighters and ASU police determined the cause of the alarm.
"I was in the [Coor] computing commons checking my e-mail when the alarms started going off," she said. "Everyone just sat there thinking this was some dumb drill."
Bankert, who was missing a sociology class, was not bothered by the inconvenience.
"We all just like to hang," Bankert said. "I don't want to be sitting here, but it's better than sitting in class."
The steam leak, which began in the basement, set off heat sensors, causing the building's unified alarm system to operate. Each room of the building has smoke and heat sensors, and when one is activated, every alarm is set off throughout the building.
ASU police spokesman John Sutton said there were no injuries or property damage.
Reach the reporter at christian.palmer@asu.edu.
