The government shutdown is starting to bite at US airports

The government shutdown is now rippling through airports across the country.

Flights at several major airports were delayed Monday because of air traffic controller staffing shortages.

Air traffic controllers and TSA employees are considered essential workers, so they're working without pay.

But Transportation Secretary Sean Duffy says there's been an uptick in the number of air traffic controllers calling in sick.

"If we have additional sick calls, we will reduce the flow consistent with a rate that's safe for the American people," Duffy said.

Duffy acknowledged the shutdown makes an already stressful job more challenging.

"They're not just now thinking about the airspace and the jobs they have to do in these towers or TRACONS or centers across the country, they're thinking about, '