Two police helicopters "collided over Berlin's iconic Olympic Stadium during a securtiy exercise," killing one of the pilots, according to the LONDON TIMES. The aircraft "crashed at low altitude during a spring snowstorm" as it "practised for operations against football hooligans." Four people were injured in the accident. A witness, John M., said on German news channel NTV: "Three helicopters were in the air. It was a real snowstorm, suddenly we heard a bang and someone shouted 'Everybody down.' Then there was blood everywhere" (LONDON TIMES, 3/21). BILD reported that the crash occured at 10:30am local time, when two helicopters from type Super-Puma and EC155 collided. They crashed on the Maifeld, which is located right next to the Olympic Stadium. A federal police spokesperson said: "The state police and prosecution have opened investigations into the cause of the accident." Germany Interior Secretary Hans-Peter Friedrich said, "Our thoughts are with the families of the victims" (BILD, 3/21).