The hashtag #5secondsofsummer trended worldwide for the first time on Twitter.
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The first official rock festival took place in the Soviet Union.
The first International Women's Day was celebrated.
The Zodiac Killer shot his first victim Mario Orosco.
Many volcanoes were discovered on one of planet Jupiter's moons called Io.
The tone poem Don Quixote by Richard Strauss premiered in Cologne, Germany.
