1928 – The Jinan incident begins with the deaths of twelve Japanese civilians by Chinese forces in Jinan, China, which leads to Japanese retaliation and the deaths of over 2,000 Chinese civilians in the following days.
1999 – The southwestern portion of Oklahoma City is devastated by an F5 tornado, killing forty-five people, injuring 665, and causing $1 billion in damage. The tornado is one of 66 from the 1999 Oklahoma tornado outbreak. This tornado also produces the highest wind speed ever recorded, measured at 301 +/- 20 mph (484 +/- 32 km/h).
2000 – The sport of geocaching begins, with the first cache placed and the coordinates from a GPS posted on Usenet.