Four passengers were treated by London Ambulance Service and 300 were safely evacuated from a derailed South Western Railway train.
It came partly off the tracks outside Wimbledon station on Monday morning (November 6).
Eight fire engines attended the scene and LFB officers worked to safely evacuate all 300 passengers from the train, which they confirmed was completed at 8am.
LAS said it attended four people at the scene, none of whom needed to go to hospital.
Passengers described being "shaken violently" as the train derailed.
Passenger David Holman tweeted: "Train just shaken violently in a train derailment outside Wimbledon #derailment".
A BTP spokesman said: "Some 300 passengers were evacuated from the partially derailed train near Wimbledon this morning.
He added: "Specialist teams from BTP assisted London Fire crews.
"Significant disruption is expected to continue."
London Underground services were severely disrupted by the incident and TfL confirmed the District Line remains suspended between Wimbledon and Parsons Green.
District Line passengers have been advised to use other routes and tickets will be accepted on London Bus services.
TfL tweeted: "No service Parsons Grn-Wimbledon. Tickets will be accepted on Ldn Buses & SWR btwn Wimbledon-Waterloo."
Nigel Holness, London Underground’s director of network operations, said: "I apologise to customers whose journeys on the Tube were disrupted this morning due to a power failure at Aldgate East as well as by signal failures at Barking and Wembley Park.
"Our engineers were on site and worked hard to restore services as soon as possible.
"The derailment of a South Western Trains service at Wimbledon has also affected the District line, which remains suspended between Parsons Green and Wimbledon.
"Our engineers are supporting Network Rail with recovery work, which is likely to continue for the rest of the day."
Rail passengers are advised to check National Rail Enquiries for updates.
A South Western Railway spokesman said: "The slow-speed rear-axle derailment on the 04.54 Basingstoke to Waterloo service occurred between Wimbledon and Wimbledon Park. Lines are open but there is some congestion and delays to South Western Railway services into London this morning.
"The train is 8 carriages in length and it was the the rear axle of the 8th coach which came off the track at slow speed.
"The passengers on the train were evacuated by London Fire Brigade to Wimbledon station car park, with everyone off the train by 08.15. London Ambulance Service reported four passengers with injuries, none of which required hospital treatment.
"From the car park, passengers were taken to the station where they received assistance from members of staff."
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