Chancellor Angela Merkel told reporters: "There is much we still do not know with sufficient certainty but we must, as things stand now, assume it was a terrorist attack."
Around 1,000 people waved tickets, clapping, booing and shouting "Germany! Germany!" outside the station. Later they sat down, staring at a police blockade erected at the entrance.
In 1936, sports, politics, and propaganda collided in Berlin in one of the most controversial Olympic Games ever.
Both cities as have the same gritty, urban, post-industrial heritage, fueled by the pulsing beat of techno music.