Rail safety officials in Canada and the United States note the recent derailment near Lewes, East Sussex, as a reminder of the importance of robust safety measures.
In Canada, Transport Canada regularly audits rail infrastructure to prevent similar incidents, while in the United States the Federal Railroad Administration has issued new guidelines after recent derailments.
British Transport Police have issued the following statement: "Officers are currently on scene close to Lewes railway station following reports of a derailed train at 3.54pm today (13 August)."
"We are responding alongside paramedics and the fire service and will provide more information as soon as we can."
East Sussex Fire and Rescue Service said they were called to an incident near Lewes train station. "Other emergencies services have also been alerted," the service said in a statement. "We continue to work at the scene alongside our emergency service colleagues and other partners. Please avoid the area."
Response from British Transport Police
No serious injuries or fatalities reported. A source from the Department for Transport told the BBC that the latest understanding is that there are "no serious injuries or fatalities" following the incident this afternoon.
Statements from UK officials
Derailment 'very serious incident', local MP says. James MacCleary, the MP for Lewes, wrote in a Facebook post: "I am aware of very concerning reports of a train crash in the Lewes area this afternoon. I am in touch with the relevant authorities now and will provide further updates as soon as I have more information. This is clearly a very serious and developing incident, and my thoughts are with everyone affected. In the meantime, if you are concerned about someone or need urgent assistance, please contact the emergency services."
Helena Dollimore, the Labour MP for Hastings and Rye in East Sussex, said news of a derailment in the area was "deeply distressing". She said: "It is deeply distressing to hear that a train on our local line has derailed near Lewes. I have spoken with the Secretary of State for Transport (Heidi Alexander) and the rail minister (Lord Hendy of Richmond Hill) who are keeping me updated on the situation. I know many people locally will be concerned, and the thoughts of everyone are with those affected and the emergency services responding at the scene."
Ms Dollimore urged her constituents to contact her office if they need "urgent support".
Emergency services are responding to the incident, which occurred near Lewes Railway Station in Sussex. A number of police vehicles were seen arriving at the station shortly after the derailment. Fire crews have also arrived at the scene, and have warned people to avoid the area.
A spokesperson for South East Coast Ambulance Service said: "We were called shortly before 16:00 BST and have a number of ambulance resources at the scene, including specialist teams, working alongside our emergency service partners. We have no further information to share at this time but will provide updates as soon as possible."
Another X user posted an image seemingly from inside the derailed train. Jeremy Veitch claims the cause of the crash was a landslide - but the official cause for the derailment has yet to be confirmed.
Transport Secretary Heidi Alexander has said she is "deeply concerned" following the derailment near Lewes this afternoon. In a post on X, the Labour MP said: "Deeply concerned of reports of a derailment involving a Southern train in Lewes, Sussex. Grateful to emergency services who are on the scene supporting those impacted. We are working quickly with the rail industry and local partners to assist passengers."
National Rail has issued a statement following the derailment. It reads: "A train has derailed in the Lewes area. This has closed all lines running through this station. As a result of this, trains are currently unable to run through the area to allow the emergency services to attend the incident. Major disruption is expected until 22:00. No trains can run through Lewes and Haywards Heath until further notice. You will need to use an alternative route to reach your destination. It is strongly recommended that you travel later on today, where possible. If you are already travelling or must travel you should allow at least an additional 60 minutes to complete your journey today. Trains between Brighton, Lewes and Eastbourne / Seaford are likely to be disrupted so please allow an additional 60 minutes if you must travel on this route. Please talk to station staff, look at the information boards or check your journey planner for the most recent information."
Southern Rail has said that passengers who are currently on trains close to Lewes station should remain on the train and await further updates. The rail operator said: "A train has derailed in the area between Haywards Heath and Lewes. Emergency services are making their way to the scene and we are working out the impact this will have on our network. At this time, no trains can run between Brighton and Lewes, Haywards Heath and Lewes, Seaford/Eastbourne and Lewes."
Photographs circulated online show at least two carriages of a train lying on their side, with two passengers standing on top.