The East Boston Tunnel (Blue Line) opened on December 31, 1904. The original terminus in downtown Boston was at Court Street Station. Streetcars would enter the subway at Maverick Square, East Boston, and then travel under the harbor to Court Street.
The Court Street terminal had only one track. A blue light in the tunnel would signal that an arriving westbound car was allowed to enter the station. Only one car was allowed in the station at a time, to reduce the risk of a collision on the single track. During the morning and evening rush hours, two streetcars were often allowed in the station at the same time.
On October 6, 1906, an accident took place in which the conductor of a streetcar was crushed to death between two cars. A car at the farthest end of the station suddenly rolled backwards, crushing the employee while he was pushing the fender in (the conductor was in the process of "changing ends," or reversing the trolley pole, interior seats, bumpers and motor, which allowed the car to head in the opposite direction on the same track). The October 7 Boston Globe describes the accident:
"[Conductor Williams, 23-years old,] was jammed between two cars at the Court-st station of the East Boston Tunnel at 8:35 yesterday morning. His legs were terribly crushed and he received such internal injuries that he died at the City Hall relief station three hours after the accident.
This is the second fatal accident that has occurred at this station since the opening of the tunnel and both occurred in exactly the same way, the conductor in each case being engaged in pushing in the fender when another car backed down and crushed him.
The Court-st station is known to the railroad men as a dead end station—that is, there is no loop. Usually only one car is allowed at the end, but in morning and evening hours it is not uncommon to have two cars come in. It was while the two cars were in yesterday that the accident occurred which caused the death of young Williams.
Williams was the conductor of a Lexington-st car and when it reached Court-st station, a Winthrop Junction [Orient Heights] car was in the dead end. The blue light, signaling for the Lexington-st motorman to enter also, was on and his car went in. Williams in the performance of his duty pulled the trolley rope and changed it for the return trip.
When a car enters the tunnel from East Boston the front fender is always out and it is pushed back at Court-st station for the return trip. Williams was engaged in pushing the fender of his car when the Orient Heights car backed down from some unknown cause and Williams was jammed between both. What railroad men were in the station pulled the Orient Heights car back and Williams was extricated.
The police were summoned and in less that 10 minutes time the conductor was at the relief station and there he was made as comfortable as possible, but there was no hope in saving his life.
Williams had been employed in the East Boston division about eight months and was highly spoken of."