MINNEAPOLIS, Aug 1 (Reuters) - A bridge carrying a four-lane state highway across the Mississippi river in central Minneapolis collapsed during rush hour on Wednesday, plunging cars and trucks into the river.

The bridge carrying Route 35W, which was under repair, buckled and fell into the river at about 6:10 p.m. CDT (2310 GMT), local media reported.

Witnesses said they heard a rumbling sound as the bridge collapsed into the river. Local media reported 20 to 30 injuries but initially no deaths.

"First I heard this huge roar," Leone Carstens, a nearby resident, told the Minneapolis Star Tribune. "I was at my computer. Initially I thought, Wow was that an airplane?"

Television pictures showed sections of highway leading to the bridge had also collapsed, in places crushing cars and starting fires and trucks.

One witness said she saw people swimming in the water seeking safety.

Huge chunks of the bridge stuck at odd angles out of the river, in places surrounded by cars half submerged in the water.

A nursing supervisor at Hennepin county medical center interviewed by local WCCO radio said, "We have multiple patients. Some critical, some non-critical," he said. Asked if there were any deaths, he said: "Not that I know of."

The road was carrying bumper to bumper traffic when the 500-foot (160 metres) steel arch bridge collapsed. The bridge, built in 1967, was 64 feet above the river.

source-http://www.reuters.com/article/bondsNews/idUSN0140206320070802

And 35W runs thru the DFW area aswell!!!!

I saw it on CNN live. There was only one lane carrying vehicles, as reported on CNN.

What could be an engineering reason?

One of my engineering guess is that A heavy truck was coming, and suddenly it noticed the closure of lanes, applied brakes. The horizontal traction was so high that it caused collapse of the bridge. Because the direction that vehicles were moving looked descending.

What else could be a reason, if the bridge is an old "enough" bridge?

Thankx god for saving me.

I really wanna share my happy feelings to you everybody out in sajha.

2 weeks ago I used to go to work in roseville using 35 W till 5.30 Pm but I QUIT that job otherwise I would have become one of the victim.

What will be the fate of our KOSHI Bridge? I think it was built more than 100 yrs ago.

i was just on that bridge last weekend going downtown... damn its no more there.

WOW, the bridge was the one I used almost every day. I lived at 1 mile from the bridge.

The steel truss of the bridge are twisted like plastic truss. What was the temperature?

I suspect the increased temperature could have weakened the supporting truss, which might have expanded it to displace beyond its safety zone at one of its support. The disastrous expansion could be the joint result of air temperature, stress and vibration. Because one of the lane was closed at that time, all rush-hour vehicles must be running through a narrow lane causing unbalance in the loads between the two parallel girders. In such a case, there is a chance to develop extra lateral stress on top of stress due to the over-crowded movement of vehicles, and the vibration therein resulting heating up of the steel structure. Once it starts softening of only a fraction of the giant girder, the whole structure start losing its stiffness in geometric order bringing the entire structure into collapse.

Any one has picture of it?

And there was a cargo train going underneath the bridge at the same time. May be the vibration created by train acted catalyst to the event…just my thought.

Any Nepali casualty(I hope not)? I have heard, there is a big Nepali community in/around Minneapolis.

yes i heard there might be some nepalis involved but they were on the edge of the bridge so nothing happened to them.

Haven't heard of any from nepali group there in Minnesota. There is a group called ANMN ... anyone from there know anything more?

http://www.cnn.com/video/#/video/us/2007/08/02/vosli.mn.i35w.bridge.collapse.side.view.cnn

any updates?

A day after the I-35W highway bridge collapsed in Minneapolis, Minnesota, rescue operations shifted to focus on recovery.

Cars were still perched precariously on various sections of the bridge as police said the recovery effort would be a long, slow process.

Cars were thrown on top of each other by the force of the bridge collapse. Investigators are treating the area as a crime scene until they determine a cause for the collapse.

Morning rush-hour traffic into downtown Minneapolis was diverted after the incident.

Two onlookers survey the damage around the site of the collapse.