Emergency crews were responding to an overturned fire engine in south Charlotte Thursday morning.
The crash happened around 8:20 a.m. near Ardrey Kell Road and Bridgehampton Club Drive.
Police have closed the road as they investigate the wreck.
MEDIC said they were transporting four firefighters to Carolinas Medical Center with potentially serious injuries. No civilians were hurt.
A picture sent to Channel 9 from a witness showed the fire engine on its roof with flames shooting into the air from its underside.