(AP) - Old photos of the Interstate 35W bridge show that two steel connecting plates were slightly bent as early as 2003 - four years before the span collapsed into the Mississippi River, killing 13 people.
Now, attorneys representing victims of the collapse are questioning when state transportation officials knew of the deformations and what, if anything, they did in response.
"Much like a bridge is not supposed to fall, a gusset plate is not supposed to be bent," said Philip Sieff, an attorney for a group of victims.
"The pictures were taken for a reason," he said, noting the up-close nature of the photos that seem to center on the plates. "It's clear there was a problem of some sort with that plate in 2003 ... if it was ignored, then someone will need to answer" for that.
"Obviously we're going to be very interested in knowing what did the state know, when did they know it, and what did they do about it."
A spokeswoman for the Minnesota Department of Transportation did not return phone or e-mail messages seeking comment Sunday.
The two photos, part of a report issued earlier this month by the National Transportation Safety Board, reveal the small bends in the pieces of steel, known as gusset plates.
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The plates depicted were at two separate connecting points that are believed to be among the first areas of the bridge to give way Aug. 1, according to NTSB documents.
"We'll be looking at what those photos tell us, if anything," NTSB spokesman Terry Williams said Sunday.
Williams said the bends in the gusset plates are just a part of the board's ongoing investigation into why the bridge fell, and he stressed that a probable cause has not been determined.
"As you can imagine, we received thousands of photographs that we've looked at," he said.
The NTSB had previously noted that the gusset plates were too thin, and officials have said they were looking into everything from the bridge's design to traffic to ongoing construction work.
The NTSB said last week that at the time of the collapse, more than 191 tons of construction material had been piled over the bridge's weakest areas.
MnDOT spokeswoman Lucy Kender didn't get back to The Associated Press, but in a story published Sunday in the Star Tribune, she declined to comment on the photos or say when the state first knew about the bent gusset plates.
The newspaper said inspection records make no mention of repairs to bending gusset plates.
The photos were posted on an NTSB Web site on March 7. Two weeks later, state transportation officials closed the Highway 23 bridge near downtown St. Cloud after inspectors found bending in four gusset plates on that span.
Kender declined to tell the newspaper whether the bent plates seen in the I-35W photos led to the emergency closure of the St. Cloud bridge.
The photos are believed to have been taken by URS Inc., a San Francisco consulting firm the state hired to examine the bridge from 2003 to 2007.
"URS and the state have both got a lot of explaining to do as far as why (the bending) was not observed, and if it was observed, why that was not immediately investigated," said James Schwebel, another attorney representing victims. "How could it possibly have been missed?"
No lawsuit has been filed, but Schwebel and Sieff both said engineering experts are studying the information, including these photos, which are stamped with the dates June 10, 2003 and June 12, 2003.
Sieff said if investigators find that the deformation played a substantial role in the collapse, "obviously we're going to be very interested in knowing what did the state know, when did they know it, and what did they do about it."
(Copyright 2008 by The Associated Press. All Rights Reserved.)