The Lewes derailment minute-by-minute: How buckled rail on hottest day of the year sent 300 tons of train and 150 screaming passengers flying off the tracks

More harrowing details have emerged of a train crash on buckled rail on Britain's hottest day of the year as fraught passengers told of their ordeal. A Southern rail service train carrying 150 passengers derailed in extreme heat yesterday afternoon in Lewes, East Sussex, leaving two people seriously injured.Travellers were left clinging on to upturned seats and handrails as three carriages came off the tracks at around 3.54pm in East Sussex.The train had set off from London Victoria at 2.24pm, heading to destination Eastbourne, though was running 20 minutes late due to heat-related speed limits.Witnesses said the carriages appeared to jump in the air before tipping on to the embankment and sliding some distance before coming to a halt.Images taken in the aftermath of the incident showed a long section of track had buckled.Passengers stood on top of the wreckage as they scrambled out of carriages that had upturned close to Lewes rail station.Some could be seen on stretchers being taken to hospital. Many of those who did not require hospital treatment were taken to a local community centre to be triaged. The cause of the derailment of the 2.24pm Southern service from London Victoria to Eastbourne has not yet been confirmed.It happened as Britain sweltered through its hottest day of the year, with temperatures above 35C (95F) in parts of Sussex and passing 38C (100.4F) in London.Early speculation focused on the possibility that the steel tracks expanded in the heat and started to warp but investigators have yet to establish what caused the train to leave the rails.Posting on Facebook today, one passenger Tracy McGregor described the derailment as 'the most frightening experience of my life'.She wrote: 'This morning I feel incredibly lucky to be okay after what happened yesterday afternoon.I was on the train that derailed near Lewes - without question the most frightening experience of my life.'I was in one of the rear carriages, which tipped onto its side and came off the tracks into a field. After tipping over, the train seemed to keep travelling at speed for what felt like ages, and we had no idea when or how it would stop.'My side window finally ended up on the ground, down in the trees - thank goodness it was a soft landing; someone said we took out a tree on the way! The rear three carriages overturned and fell off the rail track Some passengers were able to clamber through the emergency doors onto the sides of the overturned carriages'Where the train had carved through the field, the carriages were full of earth and everyone was covered in mud.'We climbed out through the doors, which were now above us, and the other passengers all joined together to lift people out. It was truly terrifying, and thank God everyone was ok.'On whether the heatwave could be a factor, logistics Professor Dr Ioannis Koliousis of the Cranfield School of Management in Bedfordshire, today said: 'Yes, extreme heat is a credible potential factor, although it is far too early to say it caused this particular derailment.'We use steel rails, which expand as temperatures rise, creating significant compressive forces.'If the track cannot adequately restrain those forces, particularly where there is an existing weakness or misalignment, buckling can occur.'Investigators will need to establish the actual sequence of events, examining track geometry, rail stress, ballast, sleepers and fastenings, maintenance records, local temperatures, recent engineering work and any heat-related speed restrictions.'We need to understand that the distorted track, which was visible after the accident, does not necessarily mean it caused the derailment because the derailing train itself could have caused substantial track displacement.' Christian Wolmar, a transport expert and author, yesterday told the Daily Mail: ‘Well, there are two possible reasons this has happened. Obviously, the train track might have buckled before the train arrived. Images appeared to show a section of badly buckled track just behind the train, with experts suggesting this may have happened due to the extreme heat 'But because the first carriages didn’t derail, it might be that the dryness from the heat has led to the embankment collapsing, and then the train made the rails buckle rather than the other way round.'I noticed yesterday when I was out on the heath for the eclipse – there's just great big fissures in Hampstead Heath, big openings like an earthquake, and that must be happening in many places.'So it could be that there's something like that that caused the embankment to partially collapse, and then the rails buckled under the weight of the train because the rails were unsupported.'He added this 'could be the more likely explanation given that the first four carriages didn’t go down'.Norman Baker, a former Lewes MP and ex-transport minister, also suggested the derailment may have been caused by a section of the track buckling in the heat.He told Times Radio: 'They'll want to make sure that the railways are completely safe before any trains are allowed back on them and if it has been the case, that the rails have buckled, that will take considerably longer to repair.'One passenger described the moment she was suddenly thrown from her seat after hearing a 'loud bang'.Yana Ludwig, 56, from Washington State in the US, said: 'It was completely terrifying. I was coming back from London and Lewes is my stop. The rear carriage skidded furthest down the embankment'There was a banging noise and everything went topsy turvy. There was lots of shaking – it felt like a really long time, but it was probably only about 10 seconds.'I landed on top of somebody. I'm just glad nobody was killed. It felt like it was maybe 20 minutes before the emergency services started showing up. It could've been faster – time is kind of warped.’Rob Bradley was travelling from London to Eastbourne with his six-year-old daughter Mabel when the crash happened and said they were in the fourth carriage while the fifth overturned.He said his daughter had been dancing between the fourth and fifth carriages just 30 seconds before the derailment. Mr Bradley said: 'As she sat down, we felt the train speeding up and started to rock - then our carriage jumped vertically upwards and we could tell it was a derailment.'The emergency brakes went on the train and everything got thrown forward. The train skidded for quite a while before it stopped.'We turned around and we saw the whole back of the train was open and smoke and dust were pouring into the carriage and we saw the fifth carriage had gone on its side.'Another passenger, father of two Liton Miah from Eastbourne, said he had been travelling with his wife and daughters to visit relatives in London when the train overturned. BTP chief superintendent Dominique Ioannou (right) speaks to the media on Thursday, alongside Network Rail Sussex route director Lucy McAuliffe (left) and South East Ambulance Service deputy chief paramedic officer Michael Bradfield (centre)Mr Miah suffered heavy bruising to his side and said he had noticed a warning about a problem with the track before the crash. He said: 'I saw on the big board there was a problem with the track. I don’t know why they didn't take any precautions. I saved my family and tried to help another couple.'The guy was bleeding heavily and there was not much I could do to help him.'Transport Secretary Heidi Alexander said she was '‘deeply concerned of reports of a derailment involving a Southern train in Lewes, Sussex'. She added: '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.'The Rail Accident Investigation Branch is deploying experts to establish how the Southern service came off the tracks.A train boss has now insisted on Friday that the railway was safe in hot weather.John Whitehurst, chief executive of Greater Thameslink Railway, said derailments were 'incredibly rare'.He added that what happened 'was a very serious incident and I’m deeply saddened by it'.Mr Whitehurst told BBC Radio 4's Today Programme: 'A full investigation is now under way with the Rail Accident Investigation Branch and at this stage we’re working with them to ensure we can establish the cause but also support their investigation fully.'Obviously, the railway through that area is closed and we have specialist teams on site assessing the train and the infrastructure. I’m really sorry for the disruption that’s caused.”Asked if the railway was safe in hot weather, Mr Whitehurst said: 'The railway is safe. These types of incidents are incredibly rare.'We have control processes in place that involve inspection, temporary speed restrictions or even suspending services if that’s required.”Pictures showed rail staff, police and members of the Rail Accident Investigations Branch back at the scene in the aftermath on Friday.A passenger on the derailed train where there were 'a lot of children on board' told the Today programme the experience was 'absolutely terrifying' and she thought she 'was going to die.'Rachel Heath said: 'The train just started jostling, kind of bumping up and down, and then jostling from side to side like a seesaw, and everyone was screaming.'I just remember looking around and seeing so much panic and fear in so many people’s eyes.'I just remember thinking to myself that I was going to die.“There was about two seconds where I genuinely thought this was it, and so I went on my phone, immediately called my partner as the train was still flipping, and was just kind of in my mind as I made that call – calling to say goodbye.”South East Coast Ambulance Service deputy chief paramedic officer Michael Bradfield said on Thursday evening there had been a 'mix of injuries of varied severity' among the 20 people who went to hospital.He told a press conference in East Sussex: 'We have conveyed 18 people to several hospitals in the region.'My colleagues said there were 20 people who went to hospital – we believe there were two who have made their own way and have self-presented at hospital.'At the press conference, Lucy McAuliffe, Network Rail’s route director for Sussex, also said the railway between Haywards Heath and Lewes was likely to remain closed for some time as specialist teams carry out assessments.She told reporters: 'I understand that people will have lots of questions about what has happened today.'I would like to reassure everyone that we are working closely with the Rail Accident Investigation Branch, who are on site to establish exactly what has happened.'At the moment, it would be inappropriate to comment as to the cause of this incident but more information would be provided as soon as we can.'Major disruption between Lewes and Haywards Heath is expected until further notice, according to Southern’s website on Friday.The notice said: 'Trains are unable to run between Lewes and Haywards Heath and will be cancelled.'Lewes District Council is encouraging people to plan ahead and use other routes such as via Brighton as nearby Eastbourne hosts its annual air show this weekend.British Transport Police said on Friday afternoon that the 'serious injuries' to two people were 'not deemed life threatening' though they remained in hospital, while 18 others with less serious wounds have been discharged. Detectives are now appealing for anyone on board and have not yet spoken to police to come forward.These people who are said to have taken alternative routes home are urged to contact BTP by calling 0800 40 50 40 or texting 61016, quoting reference 521 of 13 August.BTP Assistant Chief Constable Ian Drummond-Smith said: 'Our thoughts remain firmly with those who were injured and their loved ones. On behalf of BTP, I wish them a full and speedy recovery.'The response to yesterday's derailment demonstrated the very best of our communities and emergency services.'Local Lewes residents and business owners came out in their droves to support affected passengers, providing water and refreshments in extremely hot conditions.'My thanks and appreciation go to them as well as our officers and emergency service colleagues whose professionalism ensured those on board were brought to safety in incredibly challenging circumstances.'The public can expect to see a continued police presence at the scene over the coming days as RAIB’s investigation to identify the cause of the derailment continues.'