‘Disastrous Friday’ in Tokyo: trains grind to a halt, commuters forced onto the tracks as power restoration fails and a fire worsens the chaos
Tokyo was thrown into turmoil after the Yamanote Line, one of the capital’s main rail arteries, was paralysed for more than eight hours following a failure at a power supply facility and a subsequent fire. The disruption affected more than 670,000 passengers, with many reportedly forced to get out and walk along the tracks during rush hour. JR East said it is investigating the cause in detail.

Trigger: system could not be restored, then a fire compounded the disruption
JR East, Japan’s largest rail operator, said the problem began at around 3.50am at a power supply facility responsible for the section between Shimbashi and Shinagawa stations. Power had been shut off overnight for infrastructure improvements, but staff were unable to restore the system in time before the first trains were due to run.
The situation worsened at around 8.00am, when a fire was reported at a power supply facility near Tamachi station. Firefighters took more than 90 minutes to bring the blaze under control. Authorities are now examining whether the two incidents are directly related.

AloJapan.com