Two German federal police helicopters collided this morning near Berlin's Olympic Stadium causing multiple serious injuries to officers on board, a police spokesman said.
The helicopters were taking part in a crowd control exercise above the Maifeld area that abuts the stadium when they collided at low altitude, said federal police spokesman Ivo Priebe.
The accident led to "multiple serious and some slight injuries," said Mr Priebe while declining to comment further.
One pilot died in the incident, the Bild Zeitung newspaper said today on its Web site in citing unidentified officials.