NTSB briefing

NTSB Chair Mark Rosenker
National Transportation Safety Board Chair Mark Rosenker explains why the I-35W bridge collapsed.
MPR Photo/Sea Stachura

On Jan. 15, 2008, National Transportation Safety Board Chair Mark Rosenker blamed bad design, not bad construction or maintenance, led to the collapse of the I-35W bridge in Minneapolis that killed 13 people.

The NTSB chairman says the original bridge design from the early 1960s called for supporting gusset plates that were simply too weak. While the NTSB says it knows why the bridge collapsed, it has yet to determine exactly what caused the disaster.