A 12-year-old boy became the third child to come close to death on the Tube this week after he jumped from a London Underground carriage on Monday.
The incident follows the case of another 12-year-old, seriously injured on Brixton tracks, and an eight-year-old boy who was found wandering on tracks near Stanmore station.
Shortly before 4pm on Monday, the 12-year-old stayed on a train which terminated at Queen's Park station and missed three announcements and a set of flashing lights indicating that passengers had to leave the train.
The boy was discovered on tracks between Kensal Green and Queen's Park stations
As the train left the platform to head into sidings, which are smaller, less busy lines used for trains with no passengers, the boy realised what he had done and, "afraid that he had done something wrong", climbed from the carriage connecting doors and leapt down onto the tracks.
The boy began to walk, narrowly missing a 430 volt live rail, before the train's driver noticed and got him back on board.
When station staff spoke to the boy, he told them he wanted to walk back along the tracks to Kensal Green station to retrieve his bike.
The has reignited a debate on the safety of London's tube lines, following two other near-death incidents this week.
Last Tuesday a 12-year-old girl is believed to have fallen onto tracks at Brixton, while on Saturday a boy's life was saved by a cleaner who pulled him from Jubilee line tracks at Stanmore as a train approached.
The boy was only discovered after jumping from the train on sidings
According to the train unions Aslef and the RMT, physical checks on whether carriages are empty have been cut down due to job and finance cuts.
The RMT's leader Bob Crow said that it was the driver who saved the child's life.
“With Boris Johnson mouthing sound bites about driverless trains and de-staffing the Tube at the Tory conference, yet again only the quick intervention of a driver in the North Sheds on the Bakerloo Line prevented a 12 year old boy, who had managed to shimmy up and over the ‘inner car barriers’ and out of the train, from getting hit by a moving a train or electrocuted on the rails," he said.
“Management have rightly called an investigation into this shocking incident but this does not go far enough for RMT safety reps. We want a meeting to review the whole detrainment process and a return to a safe way of working.”