1. In 1875, King Kalakaua signed the Reciprocity Treaty with the United States, which eliminated tariffs on sugar and allowed Hawaiian sugar to be sold duty-free in the lucrative American market.

2. In 1947, the US Navy took control of the Hawaiian island of Kahoolawe to use it as a bombing range. It wasn't until 1990 that the island was returned to the state of Hawaii, and efforts have since been made to restore its ecosystem.

3. On October 5, 1978, Lee Soucy, a 23-year-old Navy diver, was attacked by a shark while working on a debris-cleaning project in Pearl Harbor. Soucy survived the attack but lost his right leg and part of his left hand.

4. In 2001, the USS Missouri, the battleship on which Japan signed the surrender ending World War II, was decommissioned at a ceremony in Pearl Harbor.

5. On October 5, 2019, Hawaii became the first state in the US to ban the use of the pesticide chlorpyrifos, which has been linked to neurological damage in children. The ban will go into effect in 2022.