NTSB Chair Backs Off Assertion That Design Flaw Was "Critical Factor" in 35W Bridge Collapse

Whoops. That rust on bridge and lack of maintenance might have had something to do with the 35W bridge collapse after all. NTSB Chair Mark Rosenker is backing off from his earlier statement that a design flaw in the gusset plates was the "critical factor" in the collapse of the bridge. As reported here earlier, Minnesota Congressman Jim Oberstar took him to task for that statement.

Rosenker writes back to Oberstar in an apologetic tone, saying

"Please be assured that it was not my intent to get ahead of the ongoing NTSB investigation or to hypothesize about the root and contributing causes of the bridge collapse.

"It was not my intent to characterize this single conclusion as the possible probable cause determination of the Board."

What he MEANT to say was corrosion was not found on the gusset plates where the collapse likely started. So while the gusset plate design flaw may not have stopped the bridge from collapsing, it may not be in Rosenker's words "the straw or straws that broke the camels back."

You can read a pdf of Rosenker's letter here.