Netcare 911 paramedics and other services responded to an accident on the R55 by Blue Hills in Midrand this afternoon.
Upon their arrival they found that there were a heavy delivery vehicle and motor vehicle involved.
One person sustained critical injuries and two children were seriously injured.
All three patients were treated on scene before being transported to a nearby Netcare facility for further medical care.
Exact detail to the cause of the accident and preceding events will remain the subject of a police investigation.