Big Dig Tunnel Ceiling Collapse

On July 10, 2006, a suspended concrete ceiling panel detached from the Interstate 90 Connector Tunnel in Boston and fell onto a passenger car, fatally injuring one person.

The suspended ceiling panel weighed approximately 26 tons, had been in place since the year 2000 and was attached to the tunnel using adhesive anchors. The adhesive anchors were identified early on as the source of the failure.

CTLGroup's challenge was to determine why the adhesive anchors failed. We were hired to investigate whether there was an issue with design, installation, material quality or something else.

CTLGroup reviewed relevant standards to determine the suitability of the adhesive anchors to suspend the ceiling panel. We also reviewed the original tunnel design to assess whether the ceiling panels had been properly designed and constructed. Additionally, CTLGroup conducted laboratory testing to independently measure the performance of the adhesive anchors.

CTLGroup's many specialized testing capabilities include significant experience with concrete anchor testing. CTLGroup routinely conducts anchor qualification tests and has in-depth experience with related standards such as ASTM, ACI and ICBO. This range of experience gives a basis for CTLGroup to provide authoritative anchor evaluation not just to the construction industry but also as a part of dispute and litigation resolution.