At approx. 7:45am Harwich Fire Rescue responded to a 2 car head on motor vehicle crash with one car on fire and possible injuries involving children, on RT 6 just west of Exit 11. A total of 4 ambulances were requested by Harwich Fire Chief Norman Clarke while enroute due to the initial reports. In addition to Harwich Engines and Ambulances, Brewster Fire Heavy Rescue and an ambulance were also dispatched to the scene. Initial attempts by first arriving Harwich Police and State Police to put out the car fire with fire extinguishers were unsuccessful due to the severity of the flames, but luckily all occupants of the 2 vehicles were able to self extricate before the fire could be put out by a hand line from the Harwich Fire Engine. All patients were evaluated and treated by Harwich and Brewster medics and were transported to CCH with what appeared to be non-life threatening injuries. Traffic was shut down in both directions (Eastbound backed up to Exit 10) while the scene was worked vehicles removed. Accident is under investigation by MA State Police.