Hundreds of flights departing from and arriving at US East Coast airports are canceled or delayed after a telecommunications outage. US Transportation Secretary Sean Duffy says the disruption is linked to an outage caused by a construction mistake, with flight operations changing over time as systems come back online.

Duffy says that around 1900 GMT, flights were resuming at LaGuardia Airport and Philadelphia, while flights into Newark and JFK were paused. Reporting from FlightAware indicates Newark had 168 cancellations and 97 delays, and Philadelphia had 63 cancellations and 189 delays, as disruptions were in effect. The outage is traced to an Amtrak construction crew cutting a fiber line in New Jersey, which affects FAA communications used to manage flights.

An FAA official says the disruption involves two issues: the primary telecom line outage and a break in a backup fiber line discovered after the first failure. The FAA expects primary system restoration by early afternoon, while repairing the backup line is estimated to take about 13 hours. Outlets frame the event as a Northeast air-traffic pause triggered by the telecom failure.