A sprinkler system is being credited with saving a Maryland high school after an electrical fire broke out Tuesday night — but students still got the day off while crews cleaned up, officials said.

The Maryland State Fire Marshal’s Office said the fire happened at Queen Anne’s High School on Ruthsburg Road in Centreville around 7:15 p.m. on Tuesday, Sept. 9.

The school’s alarm company alerted 911, and a custodian also discovered the blaze after the alarm activation.

Investigators said the fire started in a rear first-floor office and was caused by “an unspecified electrical event involving a power surge protector.”

The sprinkler system extinguished the flames before they spread further.

Crews from the Goodwill Volunteer Fire Company responded with 36 firefighters and brought the situation under control in about 30 minutes.

No injuries were reported, but the school was closed Wednesday, Sept. 10, for cleanup.

The fire caused an estimated $15,000 in structural damage and another $15,000 in contents.