"Unintentionally coupled" = spin-speak for "they almost got it stopped in time..."?
Railroad Forums
Take, for example, the Orange Line tracks between Tufts Medical Center and Back Bay, where drivers have had to go particularly slow since 2019:The Southwest Corridor opened in May 1987, thirty-four years ago. For the track to have completely deteriorated to the point of needing "gauge rods" which i assume are a temporary quick fix, and for those to be corroded, there must be a water problem in that tunnel.
FTA found that portions of track displayed evidence of excessive wear and defects. These conditions were, in turn, managed through gauge rods, some of which showed signs of corrosion