THERE'S ONE THEY CAN'T BLAME ON DICK CHENEY:

Pigeon Dung's Toll on Bridge Examined (MARTIGA LOHN, 8/22/07, AP)

Pounded and strained by heavy traffic and weakened by missing bolts and cracking steel, the failed interstate bridge over the Mississippi River also faced a less obvious enemy: Birds, specifically pigeons.

Inspectors began documenting the buildup of pigeon dung on the span near downtown Minneapolis two decades ago.

Experts say the corrosive guano deposited all over the Interstate 35W span's framework helped the steel beams rust faster.

Shoot more birds.

Posted by Orrin Judd at August 22, 2007 8:01 PM