Missouri bridge demolition blast causes unexpected damage

An explosive demolition of an old Mississippi River bridge in Cape Girardeau, Missouri, reportedly caused more damage than crews had planned. The explosive demolition on the morning of Sept. 9, was supposed to drop a 671-foot span of bridge, but according to a report in the Southeast Missourian, the blast caused a chain reaction tearing out part of a concrete pier and sending one end of the remaining 314-foot span crashing into the river.

A Missouri Department of Transportation engineer quoted in the article said the additional damage may have resulted from vibration from the blast which put more stress on the bottom beam of the second span of bridge, causing it to fail.

Dem Tech of Dubois, Wyoming, reportedly performed the explosive demolition, which is part of a $2.23 million demolition of the 76-year-old bridge. All spans of the bridge were scheduled to be demolished by mid-September.