Because of the high number of federal workers employed by the aviation industry, U.S. air travel has gotten a great deal of attention during the 33-day long government shutdown.

For one thing, TSA workers have been calling out sick by the truckload. And now, air traffic controllers are warning of dire consequences — should the shutdown continue much longer.

In a joint statement, the heads of the National Air Traffic Controllers Association, Air Line Pilots Association, and Association of Flight Attendants-CWA sounded the alarm in a big way.

“In our risk averse industry, we cannot even calculate the level of risk currently at play, nor predict the point at which the entire system will break,” the statement said. “It is unprecedented.”

The National Air Traffic Controllers Association lastest statement sounds quite dire:

“…we cannot even calculate the level of risk currently at play, nor predict the point at which the entire system will break. It is unprecedented.” https://t.co/pYfDYFYMeL

— Michael Del Moro (@MikeDelMoro) January 23, 2019

The statement noted that one in five air traffic controllers are eligible to retire. And with no money coming in, there is no incentive for those employees not to leave. When that happens, the already-understaffed air traffic control ranks will not be able to handle it — according to the union heads.

“As union leaders, we find it unconscionable that aviation professionals are being asked to work without pay and in an air safety environment that is deteriorating by the day,” the statement said. “To avoid disruption to our aviation system, we urge Congress and the White House to take all necessary steps to end this shutdown immediately.”