"The contents of the room have burned, and it has scorched the room, ceiling tiles, walls and the furniture," said Garner PD Battalion Chief Steve Williams.
Seven units from the Garner and Fairview fire departments battled the blaze which also filled other parts of the building with heavy smoke.
"We had a problem ventilating because it's such a big building and roof access. We had to actually make a hole for smoke to come out," said Williams.
Williams said the damage is not limited to the single classroom.
"That hallway, the 200 hallway, every room on that hallway has experienced some kind of damage, smoke or water," he explained.
Investigators said the cause of the fire appears to be accidental, but the exact cause is unknown.
Rand Road Elementary is a year-round school and is not currently in session. Classes are set to start on August 1. School officials say they plan to open on time.
Experts say it will be a big job to recover.
"How much water's to be removed, how much structure needs to be removed, how much structure's save-able and can be dried. So it can be anywhere from weeks to months. It just depends on the extent of the damage," explained Sue Williams with Sparkles Restoration.