MINNEAPOLIS, Minnesota (CNN) -- Federal investigators questioned construction crews that were working on the Interstate 35W bridge over the Mississippi River when it collapsed last week, while divers Sunday continued their search for victims of the disaster.
Rescue divers search for victims of the collapsed bridge Sunday.
Authorities have identified eight people reported missing and say there may be more.
An FBI forensic dive team was en route to Minneapolis to help analyze the location of any victims found in the water, where visibility is as little as 6 inches in some areas, Hennepin County Sheriff Rich Stanek said Sunday.
In addition, a five-person military assessment team is on its way to Minneapolis and is expected to arrive Sunday evening, military officials said. The team will determine how to fulfill state's request to recover cars and whether a Navy ship could help.
Up to 11 automobiles remain partially or totally submerged in the river.
Answering Minnesota Gov. Tim Pawlenty's request, the Navy is assembling a team of up to 20 divers who could be sent to the scene as early as Monday, military officials said. Watch as the search for victims and clues continues »
Churchgoers on Sunday prayed for the victims of the bridge collapse, both living and dead.
"We remember those who are still missing. We remember those who are badly injured," Pawlenty told hundreds gathered Sunday night for an interfaith service at St. Mark's Episcopal Cathedral.
Federal investigators are trying to compose a precise computer model of the bridge at the time of the collapse -- including external factors such as the weather -- to explain why the six-lane span shifted, buckled and collapsed during Wednesday's evening rush hour, killing at least five people.
"It's going to be a slow, tedious investigation," National Transportation Safety Board chairman Mark Rosenker told CNN's "Late Edition with Wolf Blitzer."
A thorough inquiry could take more than a year to conclude what happened, he said.
"We will ultimately, I really believe, understand what happened here, provide a probable cause and make recommendations to prevent it from happening anywhere else in the United States," Rosenker said.
Before the collapse, part of the bridge shifted more than 80 feet to the east in what Rosenker called "an interesting collapse pattern."
"We examined as much as we possibly can, and we have not found anything," Rosenker said. "We are going to get, we believe, significantly more clues when MNDOT [the Minnesota Department of Transportation] begins to bring up the deck and also the superstructure, which is in the water."
He said there is "significant interest" in that part of the bridge.
At a news conference in Minneapolis, Rosenker said Sunday the NTSB has started interviewing workers and officials with the construction company that was repairing the deck of the bridge.
Nighttime construction took place on the bridge Tuesday night and was to take place Wednesday night as well. As a result of the ongoing construction, only two lanes were open at the time of the collapse.
Rosenker said the NTSB is trying to establish how many trucks and how much construction equipment had been left on the bridge as part of the project, as well as the size and weight of all construction material.
Investigators are also using a high-resolution camera on the north side of the bridge to get an accurate picture of exactly where the steel superstructure collapsed, Rosenker said. If questions about that section still remain after those steps are taken, a piece could be cut from the structure and sent to Washington for further analysis, he said.
President Bush surveyed the huge chunks of concrete and twisted metal Saturday and pledged that the federal government would "eliminate roadblocks" and "cut through paperwork" to rebuild the bridge as quickly as possible.
The eight people named as missing are:
Also Saturday, family members of eight people still missing after the collapse were brought to the bridge site for the first time.
A vehicle belonging to one of the victims was removed from the water Saturday, but nothing was found inside. The other victims have been placed at the scene of the collapse from those who talked to the victims or from cell phone records, said Capt. Mike Martin, commander of the investigation into the collapse.
Officials hope to award a contract for rebuilding the bridge in Minneapolis by mid-September, and believe the new structure could open in late 2008, Bob McFarlin, a spokesman for the Minnesota Department of Transportation, said Saturday.
Construction will start as soon as possible after the contract is awarded, he told reporters, but the timetable will depend on how quickly debris can be removed.
The 35W bridge had been scheduled for major rehabilitation or replacement in 2020, McFarlin said.
Pawlenty told CNNs "Late Edition" on Sunday that the process of inspecting five other bridges of similar design in Minnesota is under way.
He also said he has ordered "a top-to-bottom review" of the state's inspection process.
"We're going to make sure that we do it right here in Minnesota," he said. "We have one of the better bridge inspection programs in the country. But obviously, even our system needs to be reviewed to make sure it is doing its best job possible." E-mail to a friend
CNN's Barbara Starr contributed to this report.