A small fire caused big headaches at a southwest Atlanta elementary school Wednesday.

The fire that broke out around 8 a.m. in a kindergarten restroom at Continental Colony Elementary School forced the evacuation of the school on Hogan Road.

Atlanta fire Battalion Chief Douglas Hatcher said there was a “real small fire of a couple off rolls of toilet paper in a boy’s bathroom that set off a sprinkler head.”

“It just kind of filled up the hallway with smoke,” Hatcher told the Atlanta Journal-Constitution.

Hatcher said there was a “little bit of water damage in the back of the bathroom itself. Other than that, there are no injuries and no other damage.”

The school had already been evacuated when firefighters arrived, Hatcher said.

He said the burning toilet paper was “inside a plastic holder, and the plastics burn at a very high rate, and all the heat rises to the top of the ceiling and that’s what you want from the sprinklers is to set if off immediately and put [the fire] out so it doesn’t spread.”

Atlanta Public Schools spokesman Stephen Alford said the evacuation went smoothly.

“There was no panic and we were able to get the kids out of the school in a timely fashion,” Alford said. “All of our systems worked, and right now, we’re contacting our parents to make sure they know what’s happening at the school, and ensuring that our kids are safe.”

While the incident only impacted a small part of the building, “we are putting our kids in the auditorium and gymnasium for the remainder of the day,” Alford said.

“We’ve also rescheduled the CRCT testing for today,” he said. “We have built-in makeup days, though, so that won’t be a problem.”

Alford said arson investigators were trying to determine who set the fire.