A severed fiber line in New Jersey forced the FAA to pause flights across the Northeast on Monday, Sept. 21, 2026, and by afternoon San Francisco International Airport had logged 408 delayed flights and 29 cancellations — compounding delays already running through the Bay Area's largest hub.

The disruption originated at the FAA's Philadelphia Terminal Radar Approach Control facility, which handles arrivals and departures for Philadelphia International, Newark Liberty and Teterboro. FAA Administrator Bryan Bedford said a primary communications circuit at the facility failed. When controllers switched to the backup system, they found a backup fiber line had been cut at a New Jersey construction site.

"That fiber break is probably 13 hours to repair," Bedford said. "It's massive, I'm told. Meanwhile, we've got the new circuit ready to install now."

Verizon, which installed the cable, said the line ran alongside an Amtrak rail line and had been dug up and cut by construction crews. Transportation Secretary Sean Duffy confirmed the sequence in a statement: "An Amtrak construction crew accidentally cut into a fiber line in New Jersey which caused a telecom outage and forced FAA to pause flights in the Northeast."

The FAA initially ordered ground stops at Philadelphia, Newark and Teterboro. The restrictions then spread to John F. Kennedy International and LaGuardia in New York. Boston also felt the effects. By Monday afternoon, more than 600 flights bound for the affected Northeast airports had been canceled.

Two disruptions at once for SFO

For SFO, the East Coast outage landed on top of an existing capacity problem. The FAA was operating a ground-delay program at the airport because of low ceilings, limiting arrivals to 36 per hour. The program's advisory listed an average delay of 50 minutes and a maximum of 172 minutes.

SFO is also operating with reduced capacity because of runway construction and FAA restrictions on parallel arrivals. The affected runway is scheduled to reopen Sept. 29, ahead of the original schedule. Even so, the closure and the arrival restrictions have significantly cut the number of aircraft SFO can handle in good weather.

The Northeast outage added a second layer of disruption for Bay Area passengers connecting through the affected airports. SFO spokesperson Doug Yakel said flights between San Francisco and Newark saw 11 cancellations and six delays, while flights to JFK recorded nine delays and Philadelphia-bound flights eight.

The timing worsened the regional impact. New York is hosting the annual United Nations General Assembly, lifting international traffic volume across the region's airspace and airports.

By late Monday afternoon, Duffy said repair crews had restored the telecommunications lines and Northeast airport operations were resuming — though travelers still faced delays as airlines worked through the backlog.

Infrastructure questions resurface

The outage renewed scrutiny of the FAA's aging communications infrastructure. The agency has been upgrading the Philadelphia-Newark communications network with additional fiber connections and other backup systems intended to improve reliability — work now under way as Monday's failure showed a single construction accident could still cascade across the country's busiest airspace and into West Coast schedules.

"This incident underscores the need for additional funding to modernize aging infrastructure and prevent disruptions like this in the future," Duffy said.