The federal investigation has begun to focus on the downtown side of the Interstate 35W bridge in Minneapolis, where a segment shifted 50 feet downstream when it collapsed Wednesday, away from the rest of the wreckage.

It's not certain that the 200-foot section is the site of whatever triggered the sudden collapse of Minnesota's busiest bridge. But, said National Transportation Safety Board (NTSB) Chairman Mark Rosenker, "We're making progress once again."

The official death toll rose from four to five Friday when officials announced that they recovered the body of Paul Eickstadt, 51, of Mounds View. Eickstadt was driving the semi-trailer truck that was sandwiched by pieces of the bridge deck and caught fire. The image came to symbolize for the world the horror of the bridge failure.

Of 98 people treated, 27 remained in hospitals Friday, including five in critical condition.

Hennepin County Sheriff Rich Stanek said that after extensive interviews with families and friends, he believes that seven to nine people remain unaccounted for.

One impact of the bridge collapse has become clear as Twin Cities commuters traveling to or from the north scramble to find alternate routes.

"We are a city cut in half," Hennepin County Commissioner Mark Stenglein said Friday. Divers from several counties put in a full day Friday slowly probing the muddy Mississippi for vehicles and other victims.

"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."

Divers searching by 'braille'

Working in teams of three -- one diver with two standing by on a barge, one putting out a tether one foot at a time -- they picked their way through submerged rebar, concrete and other debris in search of bodies. They examined more than a dozen vehicles Thursday and Friday and found no more victims. At least two cars were crushed by other vehicles or pieces of the bridge and couldn't be explored.

Hennepin County Sheriff's Capt. Bill Chandler said divers were using "the braille method" in the silty river -- feeling their way through water with little more than 6 inches visibility, and communicating with their spotters through a cable that's part of the tether.

"They've got to feel their way in, find the object, get face to face with the license plate, go around the car, then in the car," Chandler said.

He said that although the U.S. Army Corps of Engineers had reduced the river level in the area to help the search, conditions were not good. "From a supervisor's standpoint, I think we're scared all the time," he said. "It's through skill more than luck that our divers are all safe. "

The Mississippi River has long been a challenge for searchers. When scuba diver Nic Harter, a 21-year-old St. Olaf College student, was lost while diving with others near St. Paul's Hidden Falls Park in November 2004, Ramsey County authorities searched with boats, divers and sonar for two weeks before scaling back to one boat daily. Still, Harter's body wasn't found until a fisherman came across it the following March, 3 miles downstream.

The search for bridge collapse victims extends downstream to the Ford Bridge, with DNR assistance. The Minnesota State Patrol is helping search by air.

At a crisis center set up by the Red Cross at the Holiday Inn Metrodome, about 20 people still hoped for word Friday about missing friends or family. "They are definitely bargaining with God," said Scott Palmer, coordinator of psychological services at St. Cloud Hospital, who was helping at the center. "They are saying, 'Please let my loved one be found safe.' "

Many of them "are pretty scared and pretty anxious," said Palmer, who helped with crisis counseling at the World Trade Center disaster and the shootings at Red Lake School. "Some were here [Thursday] and they're coming back because they find it pretty helpful."

He said he hasn't seen any anger among the families so far over the bridge failure. "I think people think it's a horrible freak accident."