VISALIA, Calif. (KFSN) -- Visalia firefighters responded to Riverway Elementary School for a commercial fire alarm at around 8:45 p.m. Friday.
Once inside, crews found water coming out of a door, consistent with a sprinkler going off during a fire, so they requested more help.
After the utilities were shut off, crews were able to safely access the attic of the building, where they found a sprinkler head that had gone off.
But there were still no signs of fire, leading firefighters to believe the sprinkler head malfunctioned.
"The sprinkler head ran for I'm going to guess 30 to 40 minutes probably, and put a lot of water actually into that area of the school building," said Battalion Chief Danny Wristen. "There appeared to be about four classrooms and a common area that were impacted by the water damage."
It's unclear what may have caused the sprinkler to malfunction, but Battalion Chief Danny Wristen says it almost never happens.
In this case, the common area was the most affected. But water also spread to neighboring classrooms underneath the doors.
Wristen doesn't think too many classroom materials were damaged.
"Most of the water that went into the classrooms was actually on the ground," he said. "It wasn't coming down from the ceiling into the classrooms, so that helped to eliminate a lot of the damage."
The damage could amount to at least $10,000.
Students return to school on Tuesday.
Visalia Unified Officials say they plan to finish cleaning up by Monday, with the hope to have students back in the affected classrooms when they return on Tuesday.
Sprinkler head malfunction leaves part of Visalia elementary school flooded