Fire crews were called to Dedicated Repair Auto Shot in Ledgeview at around 11 a.m. Wednesday for a structure fire.
The building was occupied at the time the fire broke out, but all were able to escape before fire crews arrived.
Two of those people were treated on scene for smoke inhalation. No other injuries were reported.
Initial crews quickly called for backup. In total, 10 fire departments assisted in fighting the blaze.
Officials say that because of the extreme heat, crews rotated in and out.
Another factor that made the blaze more difficult to fight was the location. No fire hydrants were located near the scene, so crews had to transport water in.
The blaze was under control by 1:25 p.m.
The cause of the fire remains under investigation.