The blaze was reported around 12:30 a.m. at Stagecoach Manor Rest Home on Old Stage Road.
Investigators said they suspect the weather may be to blame.
"We're leaning toward storm related as the cause. Possible lightning strike is what we're leaning toward," said Chief Zachary Lindsey with the Angier & Black River Fire Department.
The residents were moved to an emergency shelter just down the road at Piney Grove Chapel Baptist Church.
The American Red Cross is on the scene providing assistance.
"The Red Cross has been very good. We do have the portable oxygen units and all their medications. We were able to bring that from the facility, along with the records that are required," said rest home administrator Buddy Lockamy.