Construction Work Will Be Crucial Part Of Investigation Into Minn. Bridge Collapse

Sunday, August 5th 2007, 2:26 pm

By: News On 6

MINNEAPOLIS (AP) _ Heavy trucks, loaders and paving equipment from Progressive Contractors Inc. had been on part of the Interstate 35W bridge since June, and workers with jackhammers had been pounding away at its deteriorated sections of concrete pavement.

It was near the end of one of their shifts that the eight-lane span collapsed into the Mississippi River, taking 18 Progressive employees with it. One of the workers is feared dead.

Now their work on the structure has become part of the National Transportation Safety Board's investigation of the bridge's collapse.

The roadway project is only one item on a long list of possible causes that also includes aging steel, deteriorating welds, vibration from adjacent train tracks and even the corrosive effects of bird droppings.

On Sunday, the NTSB said it had interviewed company officials and workers and was analyzing construction and maintenance documents.

Employees of Progressive, based in St. Michael, Minn., have helped investigators map out the locations of its equipment, vehicles and materials at the time of the accident, and how much each piece weighed. The company's work at the time was concentrated on a section of bridge over the river toward the southern end, said NTSB chairman Mark Rosenker.

Rosenker called the interviews ``quite informative'' but declined on Sunday to say what they revealed.

Progressive lawyer David Lillehaug said there is no reason to think the project had anything to do with the collapse. The most recent jackhammering of deteriorating concrete had occurred the day before, and none was performed the day of the accident, he said.

``All the reporting over the past couple of days has been with the failure of the structural steel,'' Lillehaug said.

The contract required Progressive to repair the bridge deck, replace the concrete surface and expansion joints and work on the anti-icing system, said Minnesota Department of Transportation spokesman Kevin Gutknecht.

Company officials said the crew had been preparing to pour a 2-inch layer of concrete.

Both Gutknecht and Lillehaug declined to provide additional details about the project.

The work was being done in segments, using industrial saws to cut around damaged sections of concrete, then using jackhammers to remove the severed chunks, said Glen D. Johnson, business manager for International Union of Operating Engineers Local 49, whose members were among the Progressive crew.

``There were hunks in there they just basically chip out, they jackhammer it out, smooth it off and put a new coat on,'' said Johnson, who said he had visited and driven past the job site regularly, most recently the day before the collapse.

Progressive, founded in 1971, does about $100 million in annual business. It works primarily for state and local governments in Minnesota and other states in the Upper Midwest, specializing in road paving and repair, bridge reconstruction and steel fabrication.

Bridge experts have a range of theories about whether such construction could have played a role in the collapse.

One who discounts a connection is structural engineer Stuart Sokoloff, owner of CTS Group in New York, a company that performs engineering failure analysis.

``If indeed the work that was going on was only patching or resurfacing, even if they're using jackhammers, I can't see how that would cause a major catastrophic failure of these massive (steel) trusses,'' said Sokoloff. ``I just don't put the two of them together.''