Tacoma Narrows Bridge, Suspension bridge in Tacoma, United States.

The Tacoma Narrows Bridge is a suspension bridge carrying the westbound lanes of State Route 16 across the Tacoma Narrows strait between Tacoma and the Kitsap Peninsula in Washington State. Its two pale yellow steel towers have solid vertical legs joined by X-shaped cross-braces and rest on wide concrete bases at the water. Main cables sweep from the tower tops, with vertical suspenders dropping to a long deck built as a crisscrossing steel truss.

The first bridge from nineteen forty collapsed only months after opening due to aerodynamic oscillations. A new design replaced the failed structure ten years later using reinforced truss girders instead of the original shallow stiffening beams.

The 1950 span and its 1940 predecessor were jointly named a Historic Civil Engineering Landmark by the American Society of Civil Engineers in 2012. The earlier bridge's nickname, "Galloping Gertie", came from the oscillations drivers felt during its construction. The replacement's design was tested on scale models in a wind tunnel built at the University of Washington.

Crossing relies entirely on electronic toll systems with no tollbooths on the roadway. Traffic patterns shift during morning and afternoon commute hours from nearby military installations and peninsula residents.

The collapse of the original structure was filmed by chance by a professor and the footage remains a teaching tool in engineering courses worldwide. The recording shows a metal structure moving in waves like fabric in the wind before finally falling into the depths.