Thousands of flights across the USA were grounded on Friday after a failure in air traffic control systems. The Federal Aviation Administration said there were problems with communications equipment. More than 3,500 airplanes were already in the air. Thousands of flights were cancelled, leaving passengers stranded. The problem was traced to the replacing of old copper wires with fibre-optic cables. It will take days for things to return to normal.

The incident made people worry. Officials reassured people it was not another 9/11. They said there was no sign of a cyberattack or security threat. They called the incident a "telecommunications outage". The transportation secretary blamed the failure on outdated infrastructure. He said: "It's an old system that went down. It got overloaded." The secretary warned that systems would "continue to break" unless he got allocated extra funds.