Track 'defect' that derailed train in Lewes was caught on CCTV of earlier commuter service, investigators reveal

See more Daily Mail on Google - save us as a Preferred Source Published: 07:46 EDT, 19 August 2026 | Updated: 08:28 EDT, 19 August 2026 A rail track defect existed in the area where a train derailed in East Sussex and injured 30 people - and was caught on the CCTV of another service less than two hours earlier, investigators revealed today.An interim report by the Rail Accident Investigation Branch (RAIB) said CCTV images from preceding services on the line show the fault, which it described as a 'track geometry irregularity'.It published an image appearing to show the track had already buckled, which can happen during high temperatures.The crash happened last Thursday on the UK's hottest day of the year so far as temperatures hit 38.1C in London.The RAIB noted that there has been 'a sustained period of hot and dry weather', and the nearest weather station to the scene of the accident recorded the ambient air temperature at the time as about 27C.Following the accident, investigators have received 'several reports of rough riding' from passengers on other trains at the same location, the RAIB said.Preliminary analysis of the derailed train's onboard data recorder show it was travelling at about 65mph as it approached the point of derailment in Lewes at 3.54pm last Thursday.About 150 people were onboard the eight-carriage Southern train from London Victoria to Eastbourne. Three carriages ended up on their side, trapping passengers.Aerial view of the scene near Lewes after two people were seriously injured by the derailment Investigators are looking into whether the tracks expanded in the heat and started to warp A total of 30 people were injured, included 20 who required hospital treatment, the RAIB said. British Transport Police previously said two people sustained serious injuries which were not deemed to be life-threatening.Rear-facing CCTV from an earlier train which passed the accident location at about 2.04pm on the same afternoon showed the 'track' irregularity next to white ballast bags.The RAIB said its investigation will consider the weather conditions, which were hot and sunny, as well as the status of the track, embankment, condition of the train and the effectiveness of any measures taken to address potential issues caused by hot weather.The RAIB completed its work at the site on Saturday and handed it back to Network Rail while its investigation continues. After the update today, a joint statement was issued by Lucy McAuliffe, Sussex route director at Network Rail, and John Whitehurst, chief executive officer at Greater Thameslink Railway, which operates Southern. Rear-facing CCTV from an earlier train which passed the accident location at about 2.04pm on the same afternoon. The 'track' irregularity can be seen next to the white ballast bags. A British Transport Police scene manager and investigators at the scene near Lewes last weekThey said: 'We are very sorry that this happened on our railway. Our thoughts remain with everyone affected, especially those who were injured and the family and friends of those on board the train.'We also recognise the ongoing impact the incident has had on customers, local communities and railway colleagues.'Safety is and will always remain our highest priority. While Britain's railway is one of the safest in the world, when incidents like this occur it is essential that we understand exactly what happened and identify any lessons that can be learned.'We will carefully consider any recommendations arising from the investigation and work across the industry to implement them, with the shared goal of making an already safe railway even safer for our customers, colleagues and the communities we serve.'The Lewes incident was one of two derailments in less than 24 hours as the rail network struggled in the intense heat. A Greater Anglia train derailed at 2.12pm last Friday south of Wickford railway station in Essex.The rear carriages of that train derailed in an upright position and no injuries were reported, but the line remained closed this week.