some 60 000 tons of explosive were dropped Allied bombing Berlin Allied bombing Operation Thunderclap Allied bombing Allied bombing Allied bombing in Second World War Operation Thunderclap Allied bombing a USAAF daytime air raid on Berlin 20-50 000 people Allied bombing daylight bombing campaign against Berlin Allied bombing bombing of Berlin English bombing of Berlin Wikipedia bombing of Berlin in World War II Wikipedia Bombing of Berlin English Allied bombing Berlin Allied bombing Allied bombing Allied bombing in Second World War source Allied bombing longest bombing campaigns English Allied bombing Allied bombing Berlin English Allied bombing daylight bombing campaign against Berlin