A Southern passenger service, train 1F34, derailed approximately one mile north of Lewes station at around 15:54 on Thursday 13 August 2026. The 14:24 London Victoria to Eastbourne service had around 150 people on board.
The rear three of the train's eight vehicles derailed and overturned, coming to rest on their sides. Thirty people were injured in the accident, with 20 requiring hospital treatment, some with serious injuries. Significant damage was caused to the train and railway infrastructure.
The Rail Accident Investigation Branch (RAIB) deployed a team to the site and has since released it to Network Rail for repairs and train recovery. Data from the on-train data recorder has been downloaded and is being analysed. Preliminary analysis indicates the train was travelling at approximately 65 mph as it approached the derailment point, where the maximum permissible speed is 70 mph.
Marks on the rails are consistent with wheels climbing over the rails. CCTV images from the derailed train and preceding services show a track geometry irregularity existed prior to the accident. The RAIB is also considering the condition of the embankment, which is sensitive to moisture changes, and the sustained hot weather at the time of the accident.