Reservoir Principal Pat Saunderson said Friday that school staff investigated Thursday's fire in a bathroom and "identified the student who was responsible for causing this situation.
The principal added that we "have addressed the issue accordingly."
A fire in a paper towel dispenser in a third-floor bathroom caused evacuation of the Fulton school Thursday morning.
Howard County Department of Fire and Rescue Services spokeswoman Maria Hogg said crews were called about 10:15 a.m.
The fire was contained and put out "very quickly," Hogg said, and students returned to the building.
Hogg said trucks from two stations, a "handful" of ambulances and a battalion chief responded to the call.
"Especially when it comes to schools, we don't take any chances," she said.
The sprinkler system caused a power outage on the second and third floors of the school, said Howard County Public School System spokeswoman Rebecca Amani-Dove. In an email sent to parents, Saunderson said power was restored by 1:30 p.m.
While power was being restored, students were held in the cafeteria, gym and auditorium, Amani-Dove said, and students then had a modified class schedule for the rest of the day.