Crews on Saturday used explosives to destroy the main span of the Fairfax Bridge, which connects Platte and Wyandotte counties.
The two end spans were taken down last week.
The bridge, built in 1933, had carried southbound U.S. Highway 69 traffic. Traffic was switched to the adjacent Platte Purchase Bridge, which was built in 1957.
The demolition work is part of a joint project involving the Missouri and Kansas transportation departments to replace both bridges with one bridge, to be completed in December 2016.