The TSA callout rate hit 10% just before the shutdown ended in 2019, more than three times the normal rate. A spokesperson for the agency said it did not have similar data available, but some airports have cited unscheduled absences for longer-than-usual lines.

George Bush Intercontinental and William P. Hobby Airports have been plagued by ground stops and significant security screening delays in recent weeks due to the ongoing government shutdown.

Transportation Secretary Sean Duffy predicted Tuesday that there could be chaos in the skies next week if the government shutdown drags on and air traffic controllers miss a second paycheck.

“We’re grateful for our TSA partners who continue to show incredible professionalism under difficult circumstances,” said Jim Szczesniak, director of aviation for Houston Airports.