The rock star Mark Knopfler lay in the road screaming in agony after a crash on his high-powered motorcycle, a witness said yesterday. Knopfler: broken ribs The 53-year-old former leader of Dire Straits broke six ribs and a collarbone when his machine collided with a car in Grosvenor Road, Belgravia, central London, two days ago. The witness, who declined to be named, said: "I was waving down a cab when I saw him lying in the middle of the road with a large motor-bike on the floor next to him. "Cars were racing past him, so I ran out next...