The fire broke out around 12:30 a.m. on the 100 block of South Center Street.
Crews were called to the scene of a store with apartments above on fire.
One firefighter was taken to the hospital after pulling a muscle.
Four residents from the apartments were displaced and are being assisted by the Red Cross.
The fire appears to have started in the store area, officials say.
The cause of the blaze is under investigation.