Powers Fasterners Inc. of Brewster, NY is being charged with a single count of involuntary manslaughter in the death of a 38-year-old Boston woman. Massachusetts Attorney General Martha Coakley announced the handing up of charges this afternoon. A grand jury handed up these charges today.
Milena Del Valle was killed in July 2006 with a portion of Boston’s Big Dig Interstate-90 connector tunnel ceiling collapsed and crushed the car she was riding in with her husband.
Powers Fasteners provided the epoxy used to secure the bolts to suspend the tunnel roof ceiling.
According to the Boston Globe, the NTSB issued a safety recommendation to the company last week, calling for it to revise the packaging on its fast-drying epoxy to state explicitly that it was approved for "short-term loads" only, not long-term loads.
Last month the NTSB determined the probable cause of the July 10, 2006 ceiling collapse in the D Street portal of the I-90 connector tunnel in Boston was the use of an epoxy anchor adhesive with poor creep resistance – the epoxy formulation was not capable of sustaining long-term loads. The report released after the hours-long hearing in July said over time the epoxy deformed and fractured until several ceiling support anchors pulled free and allowed a portion of the ceiling to collapse. The use of the inappropriate epoxy formulation resulted from the failure of the contractors to identify potential creep in the anchor adhesive as a critical long-term failure mode and to account for possible anchor creep in the design, specifications and approval process for the epoxy anchors used in the tunnel.
Bruce Magladry, director of the NTSB’s Office of Highway Safety said the epoxy used for the ceiling panels had “exceptionally poor” resistance to such creeping.
The inappropriate formulation also resulted from a general lack of understanding and knowledge in the construction community about creep in adhesive anchoring systems, according to the report.
The epoxy formulation used in the ceiling panels in question was a fast-set epoxy, rather than a standard-set epoxy.