Heavy rain made the Mississippi River's currents too treacherous for divers to resume searching for victims of last week's bridge collapse, so contractors used the break Tuesday to pull up huge concrete slabs, clearing the way for divers to reach what's underneath.

Politicians, meanwhile, wrangled over how to replace a 1,900-foot highway span that once carried 140,000 cars a day.

The state Department of Transportation released a preliminary design Tuesday for the new bridge, but it showed little more than an aerial view of a 10-lane span, two lanes wider than the old bridge. It will be up to a contractor, to be chosen from an initial field of five, to flesh out the design.

The state's goal is to open the new bridge by the end of 2008, a speedy timetable that worries Minneapolis Mayor R.T. Rybak and Steve Murphy, head of the state Senate Transportation Committee.

Murphy said transportation officials appeared to be "rushing headlong" into rebuilding, and it could lead to shortcuts that compromise safety.

"They could throw up that bridge and only spend $250 million, but 10 years from now we might be back investing another $250 million in it so it functions the way we want," he said Monday. "Let's not build it fast and not to last. Let's build it to last, period."

Both men said the state also should consider adding light rail tracks to the bridge design. The state already has expansion plans for a north-south light rail line that currently runs from downtown to the Minneapolis-St. Paul International Airport.

"It's possible we could save millions of dollars by putting it on or next to this bridge, Rybak said. "Now is the time to ask that question."

But MnDOT spokeswoman Lucy Kender argued there isn't time to wait, and speed doesn't have to equal lower quality.

"Our economy, our society here, needs that bridge back up," she said.

Cars had been bumper to bumper on the bridge Aug. 1 when the span suddenly collapsed during the evening rush hour. Nine victims had been recovered by Tuesday.

The rain finally let up Tuesday, but three days of storms left the Mississippi River flowing dangerously fast, with stirred-up mud and debris that reduced visibility. While the divers were out of the water, crews were beginning to peel back the concrete and rebar so they could reach vehicles that might be trapped underneath, Hennepin County Sheriff Rich Stanek told WCCO Radio.

"Nothing about this has been easy," he said. "Every day's a new obstacle."

For the recovery teams, the weather delays have been frustrating, Stanek said. The victims and those who remain missing aren't just numbers to them.

"We refer to them by their first names down on the river's edge," he said. "You know: Christine and Vera and Richard and Scott."

The four people known to be missing have been identified as Christine Sacorafas, 45, of White Bear Lake; Vera Peck, 50, of Bloomington; Scott Sathers, 29, of Maple Grove; and Greg Jolstad, 45, of Mora. The body of Richard Chit, 20, Peck's son, was recovered Sunday.

A law firm on Monday asked a federal court to grant its experts immediate access to the Interstate 35W bridge collapse site so they can begin their own investigation that could form a basis for wrongful death or personal injury lawsuits.

The petition, filed in U.S. District Court by the firm Schwebel, Goetz & Sieben, said the firm was representing three people who were severely injured in the collapse and the families of two of the victims. A hearing on the petition was scheduled for Wednesday.