Boston ? The company that provided the epoxy blamed in the fatal Big Dig tunnel collapse was indicted Wednesday in the death of a motorist crushed by ceiling panels.

Powers Fasteners Inc. was charged with one count of involuntary manslaughter, Attorney General Martha Coakley said. The Brewster, N.Y.-based firm is the only company involved in the construction and design of the tunnel to be indicted by a Suffolk County grand jury, Coakley said, noting that the investigation remains open.

A report from the National Transportation Safety Board released last month found the July 10, 2006, collapse could have been avoided if designers and construction crews had considered that the epoxy holding support anchors for the panels could slowly pull away over time.