On this day: May 20

Published On: May 17 2013 04:26:12 PM CDT   Updated On: May 20 2014 01:00:00 AM CDT

Vasco da Gama arrives in India, Christopher Columbus dies, Norman Rockwell makes his Saturday Evening Post cover debut, HIV is discovered, and "Cheers" airs its series finale, all on this day.

OTD May 20 - Moore tornado
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Richard Rowe/Reuters

2013: An EF5 tornado strikes Moore, Okla., killing 24 people -- including seven students at Plaza Towers Elementary school. The tornado injured another 377 people and caused an estimated $2 billion in damage.

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