Investigators are now saying the Big Dig tunnel collapsed because the epoxy used to secure the ceiling allowed bolts to slip or "creep" over time.
The Boston Globe is reporting that Bruce Magladry, the director of the board’s Office of Highway Safety, said the epoxy’s ”exceptionally poor creep resistance” should have been fixed when bolt slippage was noticed in 1999 and 2001 before the tunnel opened. ”It was a missed opportunity,” Magladry said.
On July 26, 2006, the Boston Herald reported it obtained documents revealing that Big Dig officials noted six years ago that epoxy ceiling supports were failing in the same tunnel section where the deadly accident occurred, but allowed the continued use of that “superglue” system to support 3-ton concrete slabs.
Stay tuned for more updates throughout the day.