Flags flew at half staff at the Minnesota Capitol on Wednesday, one week after the Interstate 35W bridge collapsed into the Mississippi River, killing at least five people and injuring about 100.

Divers from the Navy and the FBI had joined local law enforcement divers in the effort to recover eight people who remain missing and are presumed dead among the debris.

The Navy divers returned to the river at 7 a.m. after working until 10 p.m. Tuesday and were doing "a very meticulous, hand-over-hand search of the scene," said their spokesman, Senior Chief Dave Nagle.

The FBI team had to abandon the use of the larger of their two unmanned submarines, Special Agent Paul McCabe said Wednesday. The remote-controlled vehicle — equipped with a camera, sonar, lights and a grabbing arm — was too big to maneuver amid the unstable, twisted bridge wreckage and vehicles in the murky water, he said.

Instead, FBI divers will use their smaller sub, a shoe box-sized vehicle equipped only with lights and a camera. It also has smaller thrusters which make it more susceptible to the stiff river currents.

There was no change overnight in the condition of the only victim of the bridge collapse still in critical condition, said a spokeswoman for the Hennepin County Medical Center. At least seven other victims remained hospitalized.

Flying flags at half staff at the Capitol in St. Paul — the other half of the Twin Cities — followed observances Tuesday in which church bells tolled in downtown Minneapolis as residents observed a moment of silence for the victims. At 6:05 p.m. — the time of the collapse — crowds gathered at two parks near the broken span and along an upstream bridge, removing their hats and bowing their heads.

At one observance, people threw flowers into the river and poured a vial of water into the river after blessing it.

"This is how we can really reverence the silence of the dead," said Sister Rita McDonald of the Sisters of St. Joseph.

State officials have announced tentative plans for a replacement bridge, with five lanes each way instead of four. The new bridge also might be built to accommodate future bus rapid transit or light rail service.

Officials said they will start narrowing the field of potential contractors this week and by Sept. 1 they hope to select the builder. The deal will include incentives for early completion.

Gov. Tim Pawlenty said the aggressive timeline — the goal is to have it open before the end of next year — won't mean corners are cut.

"We are going to get this bridge built safely, number one," he said at a news conference. "So we're not going to go so fast or emphasize speed that the bridge isn't done well or done correctly."

One of the heroes of the collapse, Jeremy Hernandez, got good news Tuesday. Hernandez, who dropped out of Dunwoody College of Technology when he couldn't pay the tuition, was hailed for helping evacuate a school bus full of children. The school is now offering him the chance to finish his two-year automotive technician degree for free.