The worst accident in the history of the Northwestern Pacific Railway occurred a few minutes before three o’clock Thursday afternoon September 9, 1915. A collision of two trains occurred in Corte Madera on a section of single-track about 100 feet from the entrance to the Alto Tunnel. There were about 200 passengers aboard the electric train that crashed into a string of three baggage cars being pushed by a steam locomotive to a new location.. The forward car of the electric train was telescoped for several feet. Shattered wood and glass sections were ejected, some landing up to one hundred feet distant. Passengers flew from their seats into the shattered wood and glass. Many passengers were injured, some seriously, but miraculously no one was killed. Fortunately, neither train was running at high speed. The single-track was thoroughly protected by automatic signals that were working perfectly. The superintendent of the southern division of the Northwestern Pacific declared that the motorman of the electric train deliberately passed by a semaphore warning for him to stop until another train had emerged from the tunnel.