MINNEAPOLIS -- The death toll in the collapse of a bridge spanning the Mississippi River in Minneapolis has climbed to seven, with 20 people missing as of early Thursday morning.

The entire span of the Interstate 35W bridge collapsed about 6:05 p.m. Wednesday where the freeway crosses the river near University Avenue.

Fire officials briefing reporters at about 10:15 p.m. said there were at least 60 injured and seven confirmed dead. Those numbers are expected to rise.

Emergency responders had switched from a rescue to recovery mode around 10 p.m., officials said. It was too dark and there was too much debris to continue work in the water Wednesday night. It is possible that more survivors could be found, but the chances are slim, a fire rescue official said.

Recovery crews will begin work again at 6 a.m. Thursday, with an update from officials about the search at 7:30 a.m.

Police officials said they were on Wednesday night devising a transportation plan that would move commuters in and out of downtown Minneapolis. They said they would post the plan in time for the Thursday morning commute on the city of Minneapolis Web site.

A Twin Cities Red Cross official said there had been an overwhelming response from Twin Cities residents wanting to know how they could help. He said blood supplies were adequate, but more would be needed eventually for the next possible emergency, the official said.

Homeland security officials in Washington said there are no indications of a link to terrorism. Law enforcement agents were going over the wreckage with bomb sniffing dogs Wednesday night.

Dr. Joseph Clinton of the Hennepin County Medical Center gave his last briefing of the night at about 9:45 p.m.

He said, "We had four patients who have had surgery." He said six patients were critical but stable. Some of the more severly injured victims were taken to University of Minnesota hospital, and a number of children were taken to North Memorial hospital.

Clinton said they were "still identifying people."

In all, at HCMC, there were six patients in critical condition, and 22 in non-critical.

One patient had surgery on his or her head, three had abdominal surgery and another had a chest injury that did not require surgery.

Most of the injuries were caused by falls and blunt force trauma, Clinton said.

Victims' families were gathering at a nearby downtown hotel where the Red Cross was offering assistance. The Associated Press reported that authorities said all survivors have been removed.

Minneapolis Mayor R.T. Rybak spoke to reporters shortly after 9 p.m. He has been at the incident center near the bridge most of the evening.

He promised to give updates "on the tragedy" throughout the evening.

The mayor was the first to publicly confirm that six people died, saying "This will be a tragic night before it is over." There is no word yet on how those victims died. Rybak said, "we have searched 50 cars" and that the scene is under the control of the Minneapolis police and fire departments, with resources from the county and state.

Minneapolis Police Chief Tim Dolan spoke after the mayor and said that "all survivors who were on the bridge are now off the bridge." He said all of the construction workers had been accounted for but one, and that water rescue and recovery efforts were continuing.

"We have all the resources we need at this time," he said.

Gov. Tim Pawlenty then said, "It is a catastrophe and we want to say to the families our hearts and prayers are with you and we are doing everything we can to respond to this emergency ... " The governor said he has been on the phone with the U.S. Secretary of Transportation, Mary E. Peters, and Speaker of the House, Rep. Nancy Pelosi, both of whom are offering federal help.

Pawlenty told reporters that the bridge, built in 1967, had been inspected in both 2005 and 2006 and "no structural deficiencies were identified." The inspection team felt the bridge would not need to be replaced until 2020 or beyond. The governor confirmed that the construction taking place for the last few weeks was "minor" and "cosmetic," focusing on replacing lighting, concrete, lighting and guardrails and some work on joints.

Police were telling people to leave the area amid fears of several burning vehicles in the area. A firefighter on the scene said everybody from the north side of the bridge was pulled from the scene alive and that at least 50 vehicles were on the bridge at the time of the incident.

Witnesses

One driver whose car slid down the collapsing bridge said he was lucky his brakes were able to stop his car before going over the edge into the water. As he and other drivers got out of their vehicles and climbed up the incline, they rushed to get children off a nearby school bus.

He said the kids were "crying screaming," as they were lifted out of the damaged bus. The witness said it appeared some of the youngsters were injured, bleeding, scared, but none of the injuries seemed life threatening.

The same witness said he saw a tanker truck go "head first" into the water, several other cars semi-submerged and one car on fire. Police kept people as far from the scene as possible.

One man told The Associated Press that he thought his apartment building was falling.

Another man said his near encounter with the collapse was "just too close to call." Gregory Wernick Sr. said he had driven across the span minutes before it fell and stopped to get a drink. Then he heard the commotion. Wernick said he's never seen anything like it. A Houston woman said she was sitting in traffic when she started hearing "boom, boom, boom" and then everyone was "just dropping, dropping, dropping, dropping."

Nina Jenkins, 12, was on the school bus that was on the bridge when it collapsed. She told her story to CNN. She said the bus shook violently. After it came to a stop, a man opened the back door and helped the children escape, she said.

"It was scary," she said. "It was terrifying. It was lucky because everybody survived."

The girl called her mother on her cell phone and told her the bridge had "broken."

"I was like, 'It broke?'" Christy Jenkins said. The girl responded, "Yeah, mom, it broke in half."

MDOT Report

The chief engineer told local reporters they were not doing any construction work on the structure of the bridge deck. Workers had been doing simple road repair on the pavement which started a month ago.

Sen. Norm Coleman, R-Minn., said there will be a full federal review of why the bridge collapsed. He spoke of a need for a "full forensic review." He said that hopefully it would not be the beginning of discoveries of other major structural flaws in the state's infrastructure.

A 2001 Minnesota Department of Transportation report looked at "fatigue cracking" on the bride and concluded:

"The bridge's deck truss has not experienced fatigue cracking, but it has many poor fatigue details on the main truss and floor truss system.

"The research helped determine that the fatigue cracking of the deck truss is not likely, which means that the bridge should not have any problems with fatigue cracking in the foreseeable future."

"Clearly we have major issues with infrastructure,"Coleman told KSTP TV News in Minneapolis. "Let's get focused on that."

Coleman, along with other officials, said there was no indication from federal officials that the collapse was terrorism-related. The FBI was investigating, officials said.

"Clearly that angle also has to be checked out," Coleman said.

View CNN's Coverage Of Collapse

The Rescue

Divers were immediately dispatched and worked to rescue people from their submerged cars. Rescue helicopters at the scene airlifted victims to local hospitals.

Some people were stranded on parts of the bridge that aren't completely in the water. Video from the scene also showed a freight train crushed under the collapsed bridge.

The bridge opened in 1967 and is unique because it is one continuous span of steel with no pier supports. An estimated 140,000 cars travel the roadway every day.

Emergency officials said the bridge collapse could be among the worst-ever disasters in Twin City history.

"For us, this is a big deal," Minneapolis Fire Chief Jim Clack said.

The Red Cross said it had established a phone number for the families of the victims: 612-871-7676.