An aerial view of the damage caused by a 1964 tsunami near Ecola Creek, with the Cannon Beach Elementary School shown at the top right.

The tide started to pull back shortly after 11 p.m. on March 27, 1964. For a few short moments, estuaries and river channels were emptied. Then the sea came flooding in.

Earlier that evening, a 9.2 magnitude earthquake struck near Anchorage, Alaska, sending out a tidal wave that would take some four hours to reach the Oregon Coast.

When it did, people in Seaside and Cannon Beach watched as homes were swept away and piles of sand and debris washed over roadways. While the impact was much greater in areas of Alaska and British Columbia and felt as far south as Crescent City, California, it was a lasting memory for the North Coast.

In Cannon Beach, a washed-out bridge over Ecola Creek left some residents isolated for months. In hopes of bringing back tourism, three women organized the first Sandcastle Day on the beach that June.

An exhibit on view at the Cannon Beach History Center & Museum, titled “60 Years of Sandcastles,” tells the story of the contest leading up to its return on June 15.

In the book “The Next Tsunami: Living on a Restless Coast,” author Bonnie Henderson explains that at the time, many supposed the tsunami was an isolated event.

Since then, geologic records have confirmed a pattern of earthquakes and tsunamis along the Pacific coast, with the last major event having occurred in the year 1700.

Henderson’s book begins and ends with the point of view of Tom Horning, who witnessed the 1964 event at age 10 and went on to become a geologist.

Last year, Horning wrote a column for The Astorian explaining how the 1964 wave has guided mapping and modeling that could help researchers prepare for the eventual Cascadia Subduction Zone earthquake, expected to generate a much larger tsunami.

“The recurrence interval for earthquakes in the subduction zone for the last four or five quakes has been 325 years. Importantly, it’s been 323 years since the last one hit,” Horning wrote. Make that 324.