About 30 Greenwich firefighters knocked down a classroom fire at Greenwich Catholic School on Saturday, Sept. 12, containing the blaze in roughly 15 minutes with no injuries reported.

The Greenwich Fire Department said in a social media post Saturday night that crews responded to a fire alarm at the school, located at 471 North St., at approximately 10:05 p.m. No one was inside the building at the time.

While investigating the alarm, firefighters encountered smoke and located a fire in one of the classrooms. Crews stretched several hose lines and brought the fire under control. The department said the coordinated response prevented the fire from spreading further through the school.

One classroom sustained significant damage. The specific classroom and its location within the campus have not been identified.

Greenwich Free Press reported on the department's post, which also noted the role the school's fire alarm system played in the response. The department said the alarm allowed crews to locate and extinguish the fire quickly.

The fire department's Fire Marshal's Office has opened an investigation into the cause. No determination has been made public, and no timeline for the investigation's completion has been released.

Greenwich Catholic School, a PreK through eighth-grade school on a roughly 40-acre North Street campus, has not issued a public statement about the fire or whether school operations will be affected. The school's website showed no announcement as of Sunday, Sept. 13.

Residents with information about the fire can contact the Fire Marshal's Office.