In 1965, Portland International Raceway was built on the site of Vanport City, which was destroyed by a flood in 1948. Prior to its destruction, Vanport was the second largest city in Oregon. Vanport was constructed in 1942 to house the thousands of war-time shipbuilders that Henry Kaiser, of Henry Kaiser Industries, had recruited from New York to help with the war effort. Vanport, which was constructed in under a year, was deemed 'The Miracle City.' It had its own post office, nine schools, a fire station, a 400-seat cafeteria, a 785-seat theater, a library, a hospital, fourteen playgrounds, five commercial centers, and a police station staffed by 22 officers.
The problem with this instant city was that the quality of housing and building construction left much to be desired. On Sunday, May 30, 1948, just one day after the general manager of Vanport announced that the city was "not in any foreseeable danger" from rising flood waters, a segment of the ring-like dike surrounding the city collapsed. A 12-foot wall of water rushed through the community, wiping out all of the poorly-constructed houses. The residents were never officially notified that they were in danger.