The Naka-Meguro train disaster occurred in Japan on 8 March 2000.

At around 9 a.m. on 8 March 2000, the rearmost car of an eight-car TRTA Hibiya Line (now Tokyo Metro Hibiya Line) train from Kita-Senju to Kikuna derailed on the tight curve immediately before Naka-Meguro Station.

The derailed car was then hit by the fifth and sixth cars of an eight-car Tobu Railway train travelling in the opposite direction from Naka-Meguro to Takenotsuka.

Track circuits detect the presence of a train via electric current passed through the rails, which is shorted by a train car's axle or a physical break in the rails.

In this situation, a train crew member must either warn railway signal staff of the derailment, stop other trains using a handheld signal, such as a red flag, or manually short the track circuit using a specialized equipment, such as a track circuit operating clip.