The 1930s was a good time for infrastructure works in the USA, as that vast country rapidly developed its national road system with a little help from President Roosevelt’s New Deal. Route 51 was a major north-south artery created in 1926 to connect Wisconsin and New Orleans. Ten years later, the Tennessee section was improved by the construction of a two-lane highway bridge across the Hatchie River north of Memphis. This impressive 1,220 m (4,000 ft) structure not only crossed the river, but also spanned its flood plain.
In 1974 a parallel bridge was built to provide two southbound lanes, leaving the old bridge to handle northbound traffic. Unlike the original, the new bridge did not sit on piles for its full width, instead being built with a restricted opening of around 300 m (985 ft) in the center for the main river channel.
This feature would have unexpected consequences, as it concentrated the Hatchie River’s powerful flow in wet winters. That of 1988-1989 saw particularly heavy and prolonged rainfall, causing the river to remain in flood from November 1988 to the following April. On the first day of that month, three sections of the old bridge collapsed without warning. Four cars and an articulated truck plunged over 6 m (20 ft) into the fast-moving torrent below, as a 26 m (85 ft) gap was left in the carriageway. All eight occupants of the five submerged vehicles perished.
Blame fell squarely on the Tennessee Board of Transportation, which had regularly inspected the old bridge and noted ten years earlier that the main channel of the Hatchie River had shifted, with the result that piles – the very ones that eventually failed – were permanently submerged, though they were never designed to stand in water. No remedial action was taken, and disaster ensued.
When: April 1 1989
Where: Tennessee, USA
Death toll: Eight motorists died.
You should know: The Hatchie Bridge collapse pointed to the dangers inherent in many bridges built before world war II that were reaching their sell-by date with a little help from intense modem traffic volumes. To underline the point another Tennessee bridge failed two weeks later. The wooden structure crossing the Southern Railway at Oliver Springs collapsed under the weight of a truck, killing one and injuring two.