() One of California’s busiest airports was left with no air traffic controllers as the government shutdown continues.

The control tower at Hollywood Burbank Airport did not have staff from 4:15 p.m. to 10 p.m. local time on Monday, according to The Los Angeles Times. Outgoing flights were delayed an average of two hours and 31 minutes because of the shortage, and 12 flights were canceled.

Burbank had to look to San Diego for air traffic controllers to make sure flights could take off and land safely while it experienced the shortage.

The issues at Burbank are not isolated, however. Delays in airports have been felt nationwide, with Newark’s airport seeing delays at a 19% rate. Airports in Denver, Vegas, Phoenix and Detroit have also reported similar issues.

More than 4,000 flights were delayed nationwide Monday.

Transportation Secretary Sean Duffy met with air traffic controllers Monday as well and brought them lunch before holding a press briefing. Duffy said many of the air traffic controllers he spoke to told him they were worried about not being able to pay for child care and having to call out sick, with many others looking at second jobs.

“They’re thinking about ‘Am I going to get a paycheck?’ And their paychecks should come a week from tomorrow,” Duffy said during Monday’s briefing. “Now, what they’re thinking about as they control our airspace is how they’re going to pay mortgage and car payments and put food on the table.”

Regardless of the shutdown, there are 13,000 air traffic controllers who still have to come to work without pay until it ends.