A freeway bridge carrying Interstate 5 over the Skagit River collapses in Mount Vernon, Washington.

Interstate 5 (I-5) is an Interstate Highway on the West Coast of the United States that serves as the region's primary north–south route. It spans 277 miles (446 km) across the state of Washington, from the Oregon state border at Vancouver, through the Puget Sound region, to the Canadian border at Blaine. Within the Seattle metropolitan area, the freeway connects the cities of Tacoma, Seattle, and Everett.

The Skagit River is a river in southwestern British Columbia in Canada and northwestern Washington in the United States, approximately 150 mi (240 km) long. The river and its tributaries drain an area of 1.7 million acres (690,000 hectares) of the Cascade Range along the northern end of Puget Sound and flows into the sound.

On May 23, 2013, at approximately 7:00 pm PDT, a span of the bridge carrying Interstate 5 over the Skagit River in the U.S. state of Washington collapsed. Three people in two different vehicles fell into the river below and were rescued by boat, escaping serious injury. The cause of the catastrophic failure was determined to be an oversize load striking several of the bridge's overhead support beams, leading to an immediate collapse of the northernmost span.

Mount Vernon is the county seat of and the most populous city in Skagit County, Washington, United States. A central location in the Skagit River Valley, the city is located 51 miles (82 km) south of the U.S.–Canada border and 60 miles (97 km) north of Seattle. The population was 35,219 at the 2020 census, making it the 35th most-populous city in Washington, with 62,966 people living in its urban area. It is one of two principal cities of and included in the Mount Vernon-Anacortes, Washington Metropolitan Statistical Area, covering most of Skagit County.