Thousands of passengers were caught up in chaotic scenes at Euston station after all trains were cancelled due to a person dying on the tracks.
Emergency services were dealing with the incident at Bushey station in north-west London on Wednesday afternoon.
National Rail said a number of lines running through Euston station were affected. All lines out of Euston were briefly closed due to the emergency response.
The lines later reopened with significant disruption to rush hour services.
There were severe delays on the London Overground, while customers on Southern, London Northwestern and Virgin Trains have also experienced delays and cancellations.
It is not clear when normal service will resume.
A British Transport Police spokesman said: “We were called just after 2.50pm. Officers were called to Bushey station after a person was struck by a train.
“Sadly the person died at the scene.
“We are working to identify the person so we can inform their family.
“The incident is not being treated as suspicious and a file is being prepared for the coroner.”
Euston station warned: "Disruption at Euston due to an earlier incident. Please follow your operator or @nationalrailenq for train info.
The concourse is very busy this evening and there is a one way system to get to @northernline @victorialine please follow staff instructions."
