What forced the US to ground all planes? A router switch, we now know

Airlines are still scrambling to return operations to normal after the longest and only second nationwide stop of flights in the United States since the attacks of 9/11 in 2001. More than 5,000 flights were cancelled in the US on Saturday after over 9,000 were scrapped a day earlier as the knock-on effects continued from Friday’s abrupt ground stop . The stoppage was halted after more than four hours on Friday night, but airports and carriers were still grappling with large backlogs and resulting delays. The decision to suddenly ground all planes on Friday initially triggered speculation of a cyberattack.