In 1958 a wave climbed 524 metres up an Alaskan slope

Howard Ulrich anchored his fishing boat, the Edrie, in Lituya Bay — a narrow inlet on the Alaskan coast — on the night of 9 July 1958. At a quarter past ten the Fairweather fault moved in a magnitude 7.8 earthquake, and thirty million cubic metres of rock, a cube three hundred metres on a side, broke off the mountain and fell nine hundred metres into the water. The water thrown out of the way ran up the opposite slope and stripped the forest bare to a height of 524 metres: a hundred-and-seventy-storey building.

Don Miller, a geologist with the United States Geological Survey, walked the bay over the following months and measured, trunk by trunk, the line where the dead trees ended. That line is still the highest wave mark ever recorded anywhere. It was raised by a rock falling into a funnel, not by a storm.

Three boats were anchored inside. Ulrich's, with his seven-year-old son aboard, rose with the water and came back down. Bill and Vivian Swanson's went over the sand bar at the mouth; Swanson said he looked down on the tops of the trees. The third, the Sunmore, never got out: Orville and Mickey Wagner died inside it.

The trees that grew back are shorter and paler than the old forest. From a light aircraft the 1958 boundary is still visible, a stripe running round the bay.