Following a failure, stranded c2c passengers left their trains and took to the rails. This ultimately shut down the adjacent District line.
http://news.bbc.co.uk/1/hi/england/london/6520453.stm
http://news.bbc.co.uk/1/hi/england/london/6520453.stm
Stranded commuters walk on tracks
Tube engineers were forced to cut power to tracks when stranded rail commuters left their trains and began walking along adjacent train lines.
A power problem near Barking, east London, led to the evacuation of many rail and tube passengers.
Commuters stuck on the District Line tube for more than two hours watched as overground rail passengers nearby started walking on adjacent tracks.
More than nine tube trains were affected by the problem.
A spokesman for Transport for London said: "Following a power failure on C2C services this evening, passengers started leaving C2C trains and walking along the tracks which are adjacent to District line tracks.
"For safety reasons, London Underground was forced to turn off the power to the District line tracks."