State and local authorities are investigating a suspicious bathroom fire at Hopkins School on Monday that forced the school’s evacuation. The fire, located in a second floor faculty bathroom, was extinguished by the school’s sprinkler system, Deputy Fire Chief Bill Miller said on Tuesday.

The Hayden Rowe Street school was evacuated after the sprinkler system activated the fire alarm at 9:09 a.m. Miller said the fire caused minor damage, but there was water damage in the bathroom.

“They discovered a suspicious fire in the second floor bathroom,” Miller said. Miller would not discuss details of the fire, citing the open investigation. According to the Hopkinton Police log, an arson investigator from the state’s Fire Marshal’s Office came to the scene to help investigate.

Miller said school resumed about an hour after the fire and no one was injured. “The school did a phenomenal job of evacuating the students and following all plans and procedures,” Miller said.  Police spokesman Lt. Joseph Bennett said police are continuing to investigate the fire. Bennett would not release much information, citing the fire is still under investigation. Although the bathroom is a faculty bathroom, it was also open to student use.

Jennifer Mieth, a spokeswoman for the state Fire Marshal’s Office, said the cause of the fire has not been determined, but it appears to be intentionally set.

She said school fires are not uncommon. In 2015 there were 149 school fires. The majority of which were cooking related, but many were also set fires.

“Most of them were small,” said Mieth. “Although all fires start small.”

Hopkinton Public School Superintendent Cathy MacLeod said school administrators spent the day going from classroom to classroom explaining what occurred. She said the goal was to both make the students comfortable at the school, as well as to prevent the spread of rumors