Thousands of flights across the USA were grounded on Friday after a major communications failure in air traffic control systems. The Federal Aviation Administration ordered a nationwide ground stop after problems with communications equipment. More than 3,500 airplanes were in the air at the time. Thousands of flights were cancelled, leaving passengers stranded. The problem was traced to an overloaded router, possibly as a result of maintenance to replace old copper wires with fibre-optic cables. Operations may take days to return to normal.

The incident sparked widespread concern. Officials reassured people that it was not another 9/11. The homeland security secretary said there was no sign of a cyberattack or security threat. He called the incident a "telecommunications outage". The transportation secretary blamed the failure on outdated infrastructure. He said: "We use 1980s little copper lines." He added: "It's an old system that went down. It got overloaded." The secretary warned that systems would "continue to break" unless Congress allocated extra funds. He said: "I can't build things if I don't have money."