The air traffic system meltdown at Newark Liberty International Airport last week “was the most dangerous situation you could have,” according to an air traffic controller on duty that day, as the fallout from the outage stretches into a second week.

A deadly midair collision in January between a military helicopter and a commercial airliner, and several crashes since, have prompted officials to focus on fixing the nation’s outdated air traffic control system and hiring more controllers.

Newark Airport has been experiencing major problems over the last 10 days, including a terrifying systems outage in the air traffic control operations last Monday. At one point on April 28, the Philadelphia air traffic control facility that is responsible for sorting out planes entering and