Supposedly the tail light was on the same series as the inside light... (those old cars had 95V incandescent bulbs wired in series to the 750V DC traction power). So, the rear of the train was dark.
That sounds like a very bad design when a blown interior light can take out an important tail light. In fact the whole series wiring business for interior lighting raises issues, such as the first few lamps in the chain being at such high voltages.
London Underground (subway system) had a horrendous accident in 1975 when a train smashed into a dead-end tunnel at Moorgate station. There never was a definite conclusion drawn as to the cause:
http://news.bbc.co.uk/onthisday/hi/dates/stories/february/28/newsid_2515000/2515033.stmExtra safeguards were put into place at terminal stations though. They added standard tripcocks (used to emergency brake a train going through a red light) ahead of and part way along the platforms of dead-end lines, and had them operated by an approaching train with a time delay. The delay was set so that if the train was exceeding 10 mph it would reach the midway point before the tripcock was lowered and be stopped short of the tunnel end.
