Fayetteville, N.C. — Firefighters battled a blaze late Wednesday at Douglas Byrd Middle School at 1616 Ireland Drive in Fayetteville, officials said.

The fire started in the gym around 10 p.m. and spread quickly to the cafeteria, causing the gym roof to collapse, said Cumberland County Sheriff's spokeswoman Debbie Tanna. No one was injured.

The school's fire alarm system triggered the 911 call. When they arrived, firefighters said, the flames were already so heavy, it was too dangerous to inside.

"We don’t want to hurt anybody in a fire like this, so we decide right away to stay outside and do what we can from outside and that worked well on this," Battalion Commander Scott Iverson said.

Authorities said it is possible that the fire was set accidentally. They found remnants of fireworks in a courtyard that runs between the gym and cafeteria and the main building.

"Now what caused the fire, we don’t know right now. We’re not ruling anything out, but it does not appear to be arson at this time," Tanna said. "The school suffered a lot of damage tonight."

Iverson said the school's brick walls helped keep the fire contained mostly in the gym. He did not want to send any crews into the building until the hot spots could be extinguished.

Due to previous renovations, the school's gym was piled high with desks, chairs and other materials, which made the area even more flammable, officials said.

Students are scheduled to return to the school on Aug. 25.

"As soon as the site is released from the fire investigators, we’ll go in and see to what extent our maintenance people can handle (it) or whether we need to bring in additional crews. But every effort will be made to have it ready for kids," said Wanda McPhaul, Cumberland County Schools' assistant superintendent for communications.