An 83-year-old man has been arrested after a BMW hit a girl crossing outside a school. The crash happened near Charles Dickens School in Broadstairs between 8am and 8.20am this morning. A teenager suffered serious injuries and was airlifted to a London hospital after being hit by a grey BMW on Broadstairs Road, near the junction with Green Lane. The man, who comes from the town, was arrested on suspicion of causing serious injury by careless driving and taken into custody. A police spokesman said: “Officers are appealing for anyone who saw the collision, or who was in the area and might have d…