On North America's west coast, the twin suspension Tacoma Narrows Bridge spans the Tacoma Narrows strait of Washington's Puget Sound.

The original bridge opened in July 1940, but collapsed just four months later during a windstorm due to the bridge’s elastic instability, known as aeroelastic flutter. A replacement bridge was then built in 1950 and, given its popularity, it was decided that a second, eastbound bridge should be added.

The second stretch was completed in 2007 and had a construction bill totalling $786 million, which is the equivalent of $987 million (£754m) in today’s money.