This was the biggest wave ever recorded in all of history. And scientists are worried it could happen again... The biggest wave ever recorded was documented in Lituya Bay, in the southeast of Alaska, when an earthquake triggered a series of events that resulted in a mega tsunami. History and science books consider it to be the largest tsunami of modern times. On July 9th, 1958, at 10:15PM, a magnitude 7.8 earthquake caused a rock slide of around 40 million cubic yards in the Gilbert Inlet. Rocks, glaciers, and other debris fell from an altitude of approximately 3,000 feet, and the consequences were brutal. The event resulted in the highest wave in recorded history. The mega tsunami itself measured 300 feet high, but the following breaking wave became much bigger. As the giant mountain of water traveled across the entire length of Lituya Bay, it reached a peak height of 1,720 feet near the Gilbert Inlet, then destroyed everything around it.