Passengers suffering disruption because of a huge improvement programme at Britain's busiest railway station faced extra misery on Tuesday after a points failure caused a passenger service to collide with a Network Rail engineering wagon.
South West Trains (SWT) tweeted that the delays were caused by a "points failure/operating incident" near London Waterloo.
But delayed passengers tweeted pictures of the SWT service leaning against the engineering wagon.
London Ambulance Service said it had checked over three people following the "derailment", adding: "Thankfully they did not need to go to hospital."
Meanwhile, a train at London's King's Cross Station appeared to have hit the buffers on platform nine.
Staff in high visibility overalls were gathered around the front of the train and a cordon was in place.
Station staff refused to discuss what had happened.