Air traffic controllers who lost communication with aircraft at Newark Liberty International Airport in New Jersey, leading to hundreds of delays for more than a week, are taking special government leave for traumatic situations to recover from the stress.

The controllers in Philadelphia Terminal Radar Approach Control, which coordinates planes arriving at Newark, “temporarily lost radar and communications with the aircraft under their control, unable to see, hear, or talk to them,” on Monday April 28, the National Air Traffic Controllers Association said in a statement shared with CNN.