1. International Workers' Day: May 2 is celebrated internationally as International Workers' Day or May Day, which is significant in Hawaii history as it commemorates the struggle for workers' rights and the eight-hour workday.

2. The death of King Kalākaua: On May 2, 1891, King David Kalākaua died in San Francisco, ending a crucial era in Hawaiian history. He was the last reigning king of the Hawaiian Kingdom, who played an instrumental role in promoting Hawaiian culture and tradition.

3. Tragedy strikes: On May 2, 1945, a devastating landslide occurred in Hilo, Hawaii, that claimed the lives of several people and caused severe damage to the surrounding areas. The tragedy is commemorated annually as "Landslide Memorial Day" to honor the victims.

4. The birth of a legend: Legendary Hawaiian musician, singer, and actor, Don Ho was born on May 2, 1930. He gained fame for his signature song, "Tiny Bubbles," and for promoting Hawaiian music and hospitality to the world.

5. The United States annexes Hawaii: On May 2, 1898, the United States officially annexed Hawaii, making it a US territory. The annexation was a controversial move that resulted in the displacement of the Hawaiian monarchy and the loss of Hawaiian sovereignty.