About 9 a.m. Friday, crews detonated explosives that brought down a portion of the Platte Purchase Bridge.
The demolition work is part of the project to replace the Platte Purchase and Fairfax bridges with a single bridge that connects Platte and Wyandotte counties.
Construction on the new U.S. 69 Missouri River Bridge began in the fall of 2014, and the new bridge opened to both northbound and southbound traffic in late October.
The new bridge was temporarily closed Friday until 2 p.m. while crews finished the demolition work.
Crews last month used charges to take down the northern end of the Platte Purchase Bridge, which was built in 1957. They will remove the south end of the bridge later this month or in January.
The Fairfax Bridge, which was built in 1933, was removed early last year.