Fire alarms sounded in D.H. Library around 5:25 p.m. Tuesday, causing students and staff to evacuate for more than 30 minutes while the situation was assessed.

Capt. Jon Barnwell of Campus Police said the Fire Marshall and police sourced the alarm to a pull station within the library, but did not know the exact location of the pull station.

“The problem is that that alarm sound doesn’t tell you exactly where the pull station that’s going off actually is,” he said. “So they have to go around to each pull station until they find the right one.”

Fire and police responded to and disarmed the alarm in about 30 minutes.

According to Rob Capuano, assistant head of access and delivery services for the library, this is the normal response time.

“Usually it’s within half an hour,” he said.

Capuano said the alarm is triggered by various causes.

“It’s different things. Sometimes it’s electrical; sometimes, if somebody pulls one of the switches, [the alarm sounds],” he said.

Despite two false alarms in the past two weeks, Capuano said the numbers have decreased since March.

“During the renovation, it went off every couple days,” he said. “The construction workers would set it off doing something.”

Even with the decline in numbers of alarms, students said they are still inconvenienced by having to evacuate and disrupting study time.

Sophomore in biomedical engineering Lindsey Pate and sophomore in aerospace engineering Kimberly Rosado said they were studying for a Physics 208 exam on the ninth floor of the Stacks when the alarm rang.

“We were all confused,” Rosado said.

“We didn’t know if it was real or not,” Pate added.

Pate and Rosado did evacuate for the alarm, which sounded an hour before their exam, but said it was a nuisance.

“It was a big inconvenience,” Pate said.