germany's entire national railway network was halted by a failure in the gsm-r digital communication system, the radio protocol that coordinates train movements and safety signaling across the country. the failure was not weather-related, making it a rare nationwide technical outage across a mature, heavily redundant rail infrastructure. gsm-r is legacy but still foundational to european rail; a national-scale failure from a single communication layer points to a systemic single-point-of-failure architecture that has not been adequately hardened.