Photos from NTSB's report on Big Dig tunnel collapse
The Boston Globe
This is a view of two-anchor roof hanger plates that were pulling away from the roof in the westbound Interstate 90 connector tunnel after the accident. Because of this, the board urged all states to identify locations where overhead anchor bolts are used and inspect them.
This is a view of two-anchor roof hanger plates that were pulling away from the roof in the westbound Interstate 90 connector tunnel after the accident. Because of this, the board urged all states to identify locations where overhead anchor bolts are used and inspect them.
(Photo provided by NTSB)