NTSB notes break along corrosion in I-35W gussets
by The Associated Press
 
WASHINGTON -- A newly released report by the National Transportation Safety Board shows that a pair of gusset plates on the I-35W bridge broke at least partially along lines of corrosion.

The report doesn't provide any conclusions but presents several findings. It says the west gusset plate at the L-11 node was fractured partially along a line of corrosion. The node is where horizontal, vertical and diagonal beams meet and is near the center of the bridge.

It also says the east gusset plate at the same node also fractured, with part of the fracture through the line of corrosion.

The NTSB is still investigating the bridge collapse, which killed 13 people. Agency Chairman Mark Rosenker has said a design error was ``the critical factor,'' pointing to some gussets that were too thin. The agency has also said the weight of construction materials on the bridge during resurfacing was a factor.