Thursday, August 02, 2007

35W Bridge Collapse in Minneapolis

“There but for the grace of God go I.” I’ve driven that bridge countless times, as recently as 4 weeks ago coming back from a cross-town visit to a client. It is in the center of the Twin Cities and arguably the most important bridge in town. (The I-94 bridge which also crosses the Mississippi just a little bit further south would be of equal importance.) Because of this, some thoughts immediately went to terrorism, especially since the whole bridge collapsed, not just a small span, but those thoughts have been abated somewhat this morning since a 2001 inspection report stated that the bridge needed replacement.

That more people weren’t killed is truly a miracle. A school bus with 60 kids fell; only 10 of them are in the hospital. The rest are at home with their parents.

This isn’t supposed to happen here. Not in Minnesota. Maybe in California after a quake or in some state where “political corruption” is a redundancy. But not here. We always get on MNDoT about doing a poor job of pothole repairs, not about structural failures.

Identifying the full causes will take a long time. Just accessing the bridge now is difficult as it is now in a 60 foot deep ravine with steep walls on both sides. We have three metallurgists on staff here with plenty of grey hairs between them, and plenty of experience with failure analysis. None of them are in yet at this hour, but I’m anxious to prod them for insight.

More to follow...

1 comment:

Anonymous said...

It will be very interesting to see what the cause was. It was interesting to see how the failure propagated along the length of the structure. I would have guessed that a section could fall, but the remaining structure would still be standing.