Aug 3, 2007, 3:55 GMT
Washington - An eight-lane highway bridge that plunged 20 metres into the Mississippi River during rush hour, killing at least four people, had been rated structurally troubled by the US government, officials said Thursday.
The death toll was expected to rise after Wednesday's disaster on the 40-year-old span linking the cities of Minneapolis and St Paul in the central northern state of Minnesota.
Police late Thursday lowered the estimate of the number of missing to eight people, from a number once feared as high as 30.
Strong river currents and wreckage hampered divers searching for bodies suspected in the debris, Minnesota Governor Tim Pawlenty said. Authorities said that 79 people were known to have received medical treatment for injuries suffered in the collapse.
US President George W Bush pledged federal government support to deal with 'the terrible situation' and quickly rebuild the bridge. The government offered Minnesota an initial 5 million dollars in aid for measures to help get traffic moving again.
The disaster on the heavily travelled bridge focussed attention on the nation's ageing infrastructure, including US nationwide highway system that, which is an economic lifeline.
'This is America. Bridges shouldn't just fall down,' said US Senator Amy Klobuchar, who represents Minnesota and lives less than 2 kilometres from the bridge.
Mark Rosenker, head of the US National Transportation Safety Board, said it was too early to say what caused the disaster. Experts will review video of the collapse and may reconstruct part of the bridge to help the investigation, he said.
Cracks were found in the bridge's steel in the 1990s, but the problem was addressed and did not worsen, state officials said.
When the span was last inspected in June 2006, its state of repair was rated 4 on a scale of 0-9, making it 'structurally deficient,' the US Transportation Department said. The rating signalled no imminent danger, and the ill-fated span was slated for replacement only in 2020, officials said.
'It was by no means that this bridge was not safe,' said US Transportation Secretary Mary Peters, who travelled to the disaster site. 'None of those ratings indicated that there was any kind of danger here.'
About 13 per cent of nearly 600,000 bridges in the United States are rated structurally deficient, Minnesota Congressman James Oberstar said.
State politicians paid tribute to rescuers and ordinary citizens who tried to help victims, including a woman who repeatedly dove into the river to search submerged cars. One severely injured man was able to say goodbye to his family on his mobile phone before dying, police said.
'This is a horrific incident that takes your breath away and sinks your heart,' Pawlenty told reporters.
The bridge, built in 1967 and including a 140-metre section across the river, was undergoing surface repairs when it crumbled.
The disaster sparked debate about the decaying state of the US interstate highway system, first built in the 1950s under then- president Dwight D Eisenhower.
Eisenhower, a US general in Europe during World War II, was inspired by the autobahns in Germany first built during the Nazi regime.
Officials had put the confirmed death toll as high as nine, but revised it to four early Thursday. By dawn Thursday, rescuers said they had little hope of finding more survivors in the crumpled wreckage of the steel-truss bridge.
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