Overview

• Phone alerts start today in La Ferté‑Gaucher, with the main wave on October 15 across designated communes in Seine‑Saint‑Denis, Val‑de‑Marne, Essonne, and the Beaugrenelle area of Paris.
• Test messages will clearly state they are drills, require no action, and ask recipients not to call emergency services or share unverified information.
• FR‑Alert delivers audible notifications to all phones in a targeted area, including devices set to silent, and it requires no prior installation.
• Reception timing may differ by phone model, telecom operator, and exact location, and a post‑alert questionnaire will collect user feedback to improve the system.
• The HYDROS 25 exercise, involving more than 100 partners, aims to validate the alert chain as authorities plan for a centennial‑scale Seine flood that could disrupt power, heat, water, and telecommunications.