As few as three air traffic controllers were working at Newark Liberty International Airport Monday evening, according to a published report. That’s 11 fewer than the targeted amount for that time period, The New York Times reported.

The Newark airport had hundreds of flights delayed following a telecommunications issue on Sunday, just two days after a brief outage happened on Friday.

Several times over the last year, Newark controllers lost radar or radio service, leaving them unable to talk with planes they were tracking.