Updated

The Trump administration blamed a botched replacement of old copper wire communication lines for a nationwide ground stop that caused thousands of flight cancellations and stranded hundreds of thousands of passengers. France 24 reported the explanation, which points to aging infrastructure as the cause. The administration said there was no evidence the incident was a cyberattack, and lawmakers are calling for an investigation into the state of the aviation system's communication infrastructure. Two days after the grounding, thousands of US flights remained cancelled or delayed. BBC World reported that the transport secretary said normal air-traffic operations may not be restored until Monday, later than the Sunday return officials had previously expected. The episode disrupted travel worldwide and has raised questions about the country's aging infrastructure.