Various ambulances responded to the scene, while a Netcare 911 helicopter landed shortly afterwards.
Netcare 911 said a security guard was shot in the face.
According to an eyewitness who lives across the road, she heard around 10 shots being fired.
When she looked through her window, she saw a white bakkie fleeing the scene. Four men on the back of the bakkie carried heavy rifles, she said. A driver and passenger were in the front seat.
The bakkie sped off in the direction of Thembisa via Birchleigh North.
Gauteng has seen a number of money heists since lockdown.
Two of the most visible were cash-in-transit robberies in Soweto and Roodepoort, where thieves blew up cash vehicles.
The aftermath of both scenes were captured on video