On December 18, 2017, Amtrak Cascades passenger train 501 derailed near DuPont, Washington, United States. It was the inaugural run on the Point Defiance Bypass, a new passenger rail route south of Tacoma, Washington. The bypass was intended to reduce congestion and separate passenger and freight traffic, and was designed for faster speeds and shorter travel times (saving ten minutes from Seattle to Portland) than the previous route used by Cascades.
The lead locomotive and all twelve cars derailed while approaching a bridge over Interstate 5 (I-5). The trailing locomotive remained on the rails. A number of automobiles on southbound I-5 were crushed and three people on board the train died. The train derailed a short distance from where the new route merges with the previous route.
Preliminary data from the data recorder showed that the train was traveling at 78 miles per hour (126 km/h), nearly 50 miles per hour (80 km/h) over the speed limit, when the incident happened.