18. Seongsu Bridge

Location: Seoul, South Korea

Year of Fail: 1994

Spanning the Han River, this 3,800 foot-long bridge was completed in 1979 and collapsed in 1994 due to improper welding of the steel trusses under the concrete slab roadway. 32 people died and 17 were injured when one of the slabs broke off and went crashing into the water below.