Overview
- Strong thunderstorms on June 27 struck the Saint-Quentin-en-Yvelines area and toppled around ten large trees that, with lightning, tore up several hundred metres of catenary and hit electrical installations.
- Transilien services were hit across multiple axes with the J line fully suspended between Poissy and Les Mureaux at least until July 6 and lines N, U and parts of C running on reduced or altered schedules.
- The Pontoise–Gisors corridor is being served by replacement buses and TER Pays de la Loire suspended Le Mans–Paris Montparnasse services on June 28, cancelling several Ouigo and TER trains while TGVs remain unaffected.
- SNCF and regional operators have mobilised technicians and ordered substitute buses for some branches, but capacity limits and damaged power equipment mean repairs will take days and passenger disruption will continue.
- Local officials and commuters report long waits and added journeys for daily trips, and wider power outages reported by Enedis in nearby departments add complexity to restoration work and service planning.