US Department of Transportation officials attributed the unprecedented disruption to telecommunication system failures and a data overload in legacy network routers. Marking the first nationwide ground stop of this magnitude since the aftermath of the September 11 (9/11) terrorist attacks 25 years ago, the outage threw airports into chaos. According to FlightAware, over 1,000 flights were cancelled and nearly 10,000 delayed, triggering cascading disruptions across Canada and Europe. While airborne aircraft were safely guided to landings, all departing planes were frozen at their gates or taxiways. Homeland Security Secretary Markwayne Mullin reassured the public that preliminary investigations revealed no evidence of a cyberattack or malicious intent, though the incident laid bare deep vulnerabilities in the FAA's aging infrastructure—including staffing shortages and decades-old systems that still rely on floppy disks, which the agency aims to phase out by late 2028.