The impact of the government shutdown hit travelers across the United States Monday, as air traffic controllers called out sick, closing a control tower and leading to delays at major airports.

The air traffic tower at Burbank Airport was unmanned on Monday evening as air traffic controllers begin to call out in greater numbers due to the government shutdown.

A shortage of air traffic controllers appeared to be causing delays at Hollywood Burbank Airport on Monday.

Transportation Secretary Sean Duffy reported an uptick in air traffic controllers calling in sick since the shutdown began.