MINNEAPOLIS, Aug. 3 (UPI) -- The southern end of Interstate 35W bridge in Minneapolis moved 50 feet as it collapsed, the National Transportation Safety Board reported Friday.
"We believe that as the bridge began to fall, it shifted," Mark Rosenker, NTSB chairman, said during a briefing.
Recovery operation divers searching an area upriver from the site where people, vehicles, concrete and metal into the Mississippi River Wednesday during the evening rush hour. At least five people are confirmed dead and at least 100 treated at area hospitals, officials said.
Rosenker stressed investigators did not believe the eastward shift caused structure to collapse, but are focusing on that end of the span because it fell differently.
Investigators will use a computer-generated model of the bridge to analyze pieces of the bridge as well as create failure scenarios until "we get to the right one."
Another person reported missing turned up safe at work, but Hennepin County Sheriff Rich Stanek declined to update how many still missing, the Star Tribune in Minneapolis reported.
"It's a terrible mess, quite honestly," Stanek said. "We don't know how many cars were up on the bridge when it collapsed, we don't know how many victims were inside."