The mysterious corroding Big Dig light fixtures
The overhead lights inside the tunnels are corroding at the clips that attach them to the ceiling, causing a 110-pound fixture to fall onto the highway Feb. 8., 2011. Engineers suspect that salt from the roads or the nearby ocean is causing the damage. In April 2012, the state's top highway official said that all 25,000 light fixtures in the Big Big tunnels must be replaced.
SOURCES: Analysis of Lighting Fixtures, Massachusetts Material Research, Inc.; MassDOT; Metropolitan Highway System: Stem to Stern Safety Review, Wiss, Janney, Elstner Associates, Inc.
JAMES ABUNDIS, PATRICK GARVIN/Globe Staff