An investigation is to be held into how a London Underground train travelled with 11 doors wide open.
Investigation into Jubilee line open-door Tube journey
The Jubilee Line service had passengers on board as it moved at full speed between Finchley Road and West Hampstead on 1 September.
The Rail Accident Investigation Branch (RAIB), which will carry out the probe, said the train operator was "unaware" the doors were open.
Transport for London (TfL) said it welcomed the investigation.
Footage of the train shared online by @roryfergusbrown was viewed thousands of times.
Trains on the Underground network travel at an average speed of 20mph (33kmph), according to TfL.
The journey between the two stations in north-west London usually takes about one minute.
The train driver "mistakenly used a cut-out switch that bypassed a circuit designed to prevent the train from being driven with any door open" after a fault developed in the computerised train control system, the RAIB said .
When the train arrived at West Hampstead station, the train operator was made aware of the situation by a passenger and reported it to control room staff. The train was then taken out of service.
No-one fell out of the carriages, and there were no reported injuries or damage.
The RAIB's investigation will identify the "sequence of events that led to the incident" and publish the findings on its website.
London Underground is carrying out its own investigation, which is due to conclude by the end of October, according to its network operations director Nigel Holness.
Mr Holness said: "We welcome confirmation from the Rail Accident Investigation Branch that they will be investigating an incident that occurred on the Jubilee line on 1 September."