Old friends

Heard a thump behind me, and I knew exactly what had happened. Early teenage child had run out behind van and been hit by another van. Not the drivers fault, the boys had been running across the road and through gardens, driven by adrenalin. 
Fortunately one of my U3A class was a professor of nursing and she felt him over, declared that he was OK and left him (lying in the road) with his friends and other adults until the police and ambulance arrived. 
I realised that I'm very familiar with the sound of car accidents because of the number that occur on the cross roads on the village green outside our house.