The French Land Transport Accident Investigation Bureau (BEA-TT) has announced a search into the accident. SNCF released its findings on 13 July. The company reported that the derailment seemed to have been caused by a track failure. According to SNCF, a steel fishplate connecting two rails had come loose from the station at a set of points, and had become stuck in a track switch. The third and fourth carts came off track when their wheels went over the steel plate. When the problem with the switch became known, SNCF had people check the several thousand such switches on the network.