Donald Trump became the first US president to visit North Korea while meeting Kim Jong Un.
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An unidentified object thought to be a meteoroid or comet smashed into a remote forest in Siberia and destroyed 21,528 square feet of land.
NASA launched Intelsat VA F-11 into orbit.
Charles Blondin became the first person to cross Niagara Falls by walking across a tightrope.
The first leap second was added to the UTC time system.
Tower Bridge officially opened in London.
