Four people were taken to hospital, three of those seriously injured, after a crash involving a car and a bus in Seaham.
The Great North Air Ambulance Service (GNAAS) was called to the scene of the incident at 2.05pm on August 23.
The GNAAS doctor-led trauma team treated two children, aged 2, and 10, for suspected serious head injuries before flying them to the James Cook University Hospital in Middlesbrough within 10 minutes.
An adult who had also suffered a suspected serious head injury was taken to the hospital by North East Ambulance Service (NEAS).
A third child was also taken to hospital by NEAS.