A dike holding the Columbia River broke, causing a flood that destroyed Vanport, Oregon, U.S., only five years after the city was built.

A levee, dike, dyke, embankment, floodbank, or stop bank is an elevated ridge, natural or artificial, alongside the banks of a river, often intended to protect against flooding of the area adjoining the river. It is usually earthen and often runs parallel to the course of a river in its floodplain or along low-lying coastlines.

The Columbia River is the largest river in the Pacific Northwest region of North America. The river forms in the Rocky Mountains of British Columbia, Canada. It flows northwest and then south into the U.S. state of Washington, then turns west to form most of the border between Washington and the state of Oregon before emptying into the Pacific Ocean. The river is 1,243 mi (2,000 km) long, and its largest tributary is the Snake River. Its drainage basin is roughly the size of France and extends into seven states of the United States and one Canadian province. The fourth-largest river in the United States by flow, the Columbia has the greatest flow of any river into the eastern Pacific.

Vanport, sometimes referred to as Vanport City or Kaiserville, was a city of wartime public housing in Multnomah County, Oregon, United States, between the contemporary Portland city boundary and the Columbia River. It was destroyed in the 1948 Columbia River flood and not rebuilt. It sat on what is currently the site of Delta Park and the Portland International Raceway.