On 9 July 1958, a 7.8 strike-slip earthquake in southeast Alaska caused 90 million tonnes of rock and ice to drop into the deep water at the head of Lituya Bay. The block fell almost vertically and hit the water with sufficient force to create a wave that surged up the opposite side of the head of the bay to a height of 100 feet, and was still many tens of metres high further down the bay, when it carried eyewitnesses Howard Ulrich and his son Howard Jr. over the trees in their fishing boat. They were washed back into the bay and both survived.