In Minneapolis, recovery work continues in the rubble of the 35 West bridge, which collapsed during the afternoon rush hour Wednesday. Officials have now confirmed five deaths from the disaster, with eight people still listed as missing. Among visitors to the site Friday was First Lady Laura Bush. We learn more in this report by VOA's Greg Flakus in Houston.

First Lady Laura Bush talks to first responders as she visits the site of the I-35W bridge collapse over the Mississippi River in Minneapolis, 3 Aug. 2007

"Over the last 43 hours, the whole country has seen the strength of the Minneapolis-St. Paul community, and because we have seen that strength, we all are confident that the bridge will be rebuilt and that your city will heal," she said.

President Bush is to visit the disaster site on Saturday.

The 160-meter-long bridge was located near the University of Minnesota campus and rose 20 meters over the Mississippi River. As many as 200,000 people crossed the bridge each day, traveling between the two cities. That traffic has now been routed around the disaster site.

Authorities have lowered the water level at the site by using dams and dikes installed higher up on the river, but recovery workers still face a daunting task. The broken concrete slabs and metal support beams that lie twisted and scattered under the water's surface present hazards for divers trying to locate bodies underwater. In addition, there are currents, which are actually swifter and more treacherous as a result of the water level having been lowered.

The collapse of the bridge has also wakened officials all over the country to the threat posed by bridges and other vital infrastructure that might be cracked or showing signs of fatigue as well as to the need for new inspections. Experts say there are nearly 600,000 bridges in the United States, and they have an average age of 42 years. More than 75,000 of them have ratings of "structurally deficient," as did the bridge in Minneapolis.

Authorities say that rating does not mean the bridges are in danger of imminent collapse, but that measures should be taken to either address the problems or replace them.

People in Minnesota are now asking why more was not done to repair the Minneapolis bridge, which was revealed to have problems in a 2005 inspection and yet was not listed as needing to be replaced until 2020.

The effort to determine what exactly caused the collapse is expected to take many weeks. Federal and state engineers are working together to recover material from the bridge and to study videotapes from nearby security cameras that may provide clues as to what went wrong.