Ian McEwan on yesterday.

Police were fanning out through Bloomsbury closing streets at both ends even as you were halfway down them. The machinery of state, a great Leviathan, certain of its authority, moved with balletic coordination. Those rehearsals for a multiple terrorist attack underground were paying off. In fact, now the disaster was upon us, it had an air of weary inevitability, and it looked familiar, as though it had happened long ago. In the drizzle and dim light, the police lines, the emergency vehicles, the silent passers by appeared as though in an old newsreel film in black and white. The news of the successful Olympic bid was more surprising than this. How could we have forgotten that this was always going to happen?