I-35W
Mississippi River Bridge Collapsed
2007
As
of this writing (July 2008), officials have yet to formally announce the cause
or causes of the August 2007 rush-hour collapse in Minnesota. But a preliminary
report released in January 2008 revealed that strain on the
structure's gusset plates, which held the bridge's support beams in
place, contributed to
the collapse. The gusset plates were part of a "non-redundant" design. If any major component of
the bridge failed, the structure was bound to collapse. The design of the
replacement bridge features multiple failsafes—no single part of
the structure alone bears the bridge's weight. The new bridge is also
being fitted with hundreds of sensors to track temperature, motion, strain, and
chemical wear.
