1. On April 13, 1972, Hawaii became the first state in the U.S. to ban the use of DDT, a toxic pesticide that was harmful to wildlife and the environment.

2. In 1984, the Waiahole-Waikane water dispute, a long-standing conflict between East Honolulu farmers and the City and County of Honolulu, came to a head on April 13. The farmers had been protesting the city's plan to divert water from the Waiahole and Waikane streams to urban areas, leading to a standoff between protesters and police that lasted for weeks.

3. On April 13, 1990, the first Hawaiian language immersion school, Pūnana Leo, opened its doors in Hilo. The school aimed to revitalize the Hawaiian language and culture by offering instruction in the native language to young children.

4. In 2004, a magnitude 6.5 earthquake struck off the coast of the Big Island on April 13, causing widespread power outages and damage to buildings. However, there were no fatalities or serious injuries reported.

5. On April 13, 2018, Hawaii's Kilauea volcano erupted, spewing lava and ash into the air and forcing thousands of residents to evacuate their homes. The eruption lasted for several months, causing extensive damage to homes and infrastructure in the affected areas.