Tuesday, January 29, 2008

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.

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Wednesday, January 23, 2008

Oberstar Blasts NTSB Chair For 35W Bridge Comments

The National Transportation Safety Board usually follows a strict policy of not announcing the cause of an accident until the investigation is completed. Yet last week even though the NTSB reported it had not determined the probable cause of the 35W bridge collapse, NTSB Chairman Mark Rosenker said a design flaw in the bridge's gusset plates "tells us why the bridge collapsed."

Minnesota Congressman Jim Oberstar is taking Rosenker to task for his remarks, calling them "unfortunate" and suggesting that they could compromise the NTSB's investigation.

In a letter sent to Rosenker today, Oberstar writes:
"I consider it highly inappropriate for you to have stated as you did in the press conference, that the poor design of the plates 'tells us why the bridge collapsed.' Although you admitted you do not have complete information on corrosion, you nonetheless insisted that poor design was the 'critical factor.'
"Such announcements undermine the process and create the potential for committing the board to conclusions that will be difficult to change if the subsequent investigation suggests other conclusions.
"I strongly urge you to adhere to the Board's established process of not announcing the cause of an accident until the investigation is completed."

In the letter Oberstar indicated that holding the press conference was the right thing to do since other bridges may have the same design flaw. A pdf of the letter is here

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