Alot of shots on 420:
1657 - Admiral Robert Blake destroys a Spanish silver fleet under heavy fire at Santa Cruz de Tenerife.
1775 - American Revolutionary War: the siege of Boston begins, which followed the first battles at Lexington and Concord.
1978 - Korean Air Flight 902 shot down by Soviets.
1986 - Professional basketball player Michael Jordan sets all-time record for points in a NBA playoff game with 63 against the Boston Celtics.
2007 - Johnson Space Center Shooting: A man with a hand gun barricades himself in NASA's Johnson Space Center before killing a male hostage and himself.