Which one of the following events does not happen on 3rd May?
Washington, D C is incorporated as a city in 1802
Garry Kasparov begins chess match with IBM supercomputer Deep Blue in 1997
Oklahoma City is slammed by an F5 tornado killing 42 people, injuring 665, and causing $1 billion in damage. The tornado was one of 66 from the Oklahoma Tornado Outbreak in 1999
Find the event NOT on May 3rd. The US never had a 20¢ coin in circulation in 1878 - the 20-cent piece was minted 1875-1878 but was discontinued, not 'stopped minting on May 3, 1878.' The other events are correctly dated to May 3rd: DC incorporation (1802), Kasparov-Deep Blue (May 3, 1997), and Oklahoma tornado (May 3, 1999).