Portions of the University Bookstore and US Bank at Coffman Union flooded Saturday morning when a sprinkler head malfunctioned.

Damage to the bank was in the back room, away from customers, and was mostly limited to electrical equipment.

“We’re fortunate it wasn’t out in the lobby or at the ATMs,” branch manager Eric Rediske said.

Though damage was minimal, both the bookstore and the bank were closed for the remainder of the day for cleanup.

Repair personnel told Rediske that sprinklers like the ones in Coffman Union can release up to 70 gallons of water per minute.

The sprinkler ran for at least 15 minutes before it was turned off.

Usually, a sprinkler head is activated when its sensor, a small vial of heat-sensitive liquid, detects a room temperature in excess of 145 degrees. The vial then heats up and explodes, triggering the sprinklers to douse any possible fires.

A faulty sprinkler head is rare: There is a one in 13 million chance, workers told bank personnel.

Rediske said he did not know how much it would cost to replace the damaged equipment.

Chelsie Hanstad is a freelance writer. The freelance editor welcomes comments at [email protected]