New Orleans Mayor Ray Nagin took the extraordinary step Thursday of sending a message through the media -- which he termed a "desperate SOS" -- advising the crowd at the convention center to march over the Crescent City Connection bridge to the west bank of the Mississippi River to find relief in neighboring Jefferson Parish.

CNN: vert.sandbag.drop.pool.jpg

The only remaining connection between the two sides was a railway bridge.

BBC: Flooded town's new bridge on move

"The Forth Road Bridge has provided 25 million vehicles every year with a connection between communities north and south of the Forth estuary whilst acting as a vital link in Scotland's transport network, " he said.

BBC: Forth Road Bridge