Fayetteville, N.C. — Preliminary evidence doesn't indicate arson, but investigators haven't ruled out anything else as the cause of a fire that seriously damaged Douglas Byrd Middle School overnight, said Debbie Tanna, a spokeswoman for the Cumberland County Sheriff's Office

The fire started in the gym, at 1616 Ireland Drive, around 10 p.m. Wednesday, quickly spread to the cafeteria and caused the roof to cave in, Tanna said. No one was hurt.

The ash- and soot-covered school grounds, combed over by insurance adjusters and State Bureau of Investigation agents, were an active crime scene Thursday. That is standard procedure and doesn't necessarily imply criminal activity, Tanna said.

"They're going around collecting any kind of evidence that might tell the tale of what happened here last night," Tanna said.

Investigators found remnants of fireworks in an outside corridor between the cafeteria, gym and main building Thursday morning. The gym and cafeteria were also under renovation and getting new roofing.

Investigators' task will be made more difficult by the amount of debris. The gym was full of chairs, desks and other materials teachers had stored there during the renovations.

"This was such a spectacular fire, and it's still very hot in areas," Tanna said. "It’s been inaccessible to firefighters and SBI agents to go in and see exactly what happened."

Tanna said the gym was a total loss and the cafeteria had a lot of water, smoke and fire damage.

School officials said they haven't been able to see the damage close-up but are hopeful that the classrooms were spared extensive damaged. If that's the case, the school will be able to open as scheduled on Aug. 25 for approximately 650 seventh- and eight-graders.

"That we would not have to displace students is certainly our hope," said Wanda McPhaul, a spokeswoman for the Cumberland County school system.

Principal Vanessa Alford said she is concerned about the teachers who lost all they were storing in the gym.