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4 with the throttle in run 4 or 5 position, he made a minimum 10- or 12-pounds per square inch (psi) service application of the automatic airbrakes shortly before passing the eastbound wayside automatic block signal (MP 226 2) west 0 Ruggles Street station (See figure 2) He stated that he then released the locomotive independent brake an reduced the throttleto run 1 or 2 position The locomotive engineer said that the brakes did not exhibit the normal reaction and that the train slowed only a little when it should have slowed more

The locomotive engineer instructed the apprentice engineer to make a further brake application, and the apprentice engineer made a 32-psi full-service application while passing the Ruggles Street station platform The locomotive engineer stated that they could sense that the train was not slowing down sufficiently According to the apprentice engineer, the locomotive engineer made an emergency application of the automatic airbrakes, The train moved eastward into the tunnel at MP 227 on track 2 and entered the 90 30‘ right curve near MP 227 4, 200 feet from the point of derailment (POD) The locomotive engineer said that the train entered this curve "hard" Neither the locomotive engineer nor the apprentice engineer noticed the train speed at that time. The speed restriction on all tracks (l, 2, and 3) through Back Bay station from MP 227 to MP 228 3 is 30 mph (See figure 2)

On board Amtrak train 66, neither the conductor, two assistant conductors, nor a deadhead conductor (a railroad employee traveling to a work assignment) heard an application of the airbrakes before the accident. The train 66 conductor felt the brakes apply on the train. The other crewmembers were able to state only that the train was slowing for the Back Bay station

As Amtrak train 66 moved into the curve, the locomotive crew felt the locomotive tip to the left toward track 1 As Amtrak train 66 approached the west end of the Back Bay station platform, its locomotive crew saw locomotive 1073 of the Massachusetts Bay Transit Authority (MBTA) commuter train 906 on track 1 The locomotive crew reported that events then became unclear until after the collision with the META train 906 (See figure 3)

Shortlyy before 7 45 a m, the MBTA train 906, comprising one control car, six coaches, an one locomotive, had departed Stoughton, Massachusetts, eastbound for South Station, Boston The MBTA train 906 was a push/pull operation; the locomotive was on the rear (west end) of the train in the pushing mode The MBTA train 906 operated with an Amtrak crew comprising a conductor, three assistant conductors, and a locomotive engineer The locomotive engineer was operating the train from the control car cab, which was equipped with locomotive controls, at the front (east end) of the train. The locomotive engineer stated that the MBTA train 906 was almost stopped on track 1, moving about 5 to 10 mph, at the time of the accident He was standing at the controls in the cab, felt the collision, and was knocked to the floor Not knowing exactly what had happened, he made an emergency radio call to the dispatcher.

At 8 23 am in the Boston train dispatcher's office, the Centralized Electrical and Traffic Control (CETC) system illuminated a “track occupied" light (TOL) for track 3 at Back Bay station. The dispatcher stated that before the TOL illuminated,