1. In 1917, the United States officially declared war against Germany, officially entering World War I. This had a significant impact on Hawaii, as the islands were seen as a strategically important location for the US military during the conflict.

2. In 1946, a devastating tsunami struck the island of Hawaii, causing widespread destruction and claiming many lives. The tsunami was triggered by an earthquake off the coast of Alaska, and Hawaii was one of several areas across the Pacific that was affected.

3. On April 2, 1959, Hawaii became the 50th state to be admitted to the United States. This was a historic moment for the archipelago, which had been an independent kingdom until the late 19th century, when it was annexed by the United States.

4. In 1982, the Mauna Loa Observatory on Hawaii's Big Island recorded the highest concentration of carbon dioxide in the atmosphere at that time, at 343 parts per million. This was a significant moment in the ongoing debate around climate change and the role of human activity in carbon emissions.

5. On April 2, 2011, the world-famous taro farming region of Hanalei on Kauai was hit by a devastating landslide, which caused significant damage and forced many residents to evacuate. This incident highlighted the vulnerability of Hawaii's natural landscapes and the need for careful land management practices.