May 11 edit
1953: An F5 tornado destroyed areas of downtown Waco, Texas, killing 114 people.
1970: Seventeen years to the day after the deadliest tornado in Texas history, another tornado struck downtown Lubbock, Texas, killing 26 people. It was the only F5 tornado in history to strike a skyscraper, which had its steel infrastructure twisted by the storm.
1996: A severe blizzard killed eight people near the summit of Mount Everest.