The shutdown has taken a toll on the staffing levels of air traffic controllers, with roughly 13,000 working without pay.

U.S. Transportation Secretary Sean Duffy spoke out about SEPTA in a press conference Tuesday addressing major safety and management concerns.

The Department of Transportation might be forced to shut down the airspace in certain parts of the country if the government shutdown continues into next week.

Transportation Secretary Sean Duffy said the agency may need to close "certain parts of the airspace" if the shutdown continues.

Duffy said the shutdown — which is currently tied for the longest shutdown in U.S. history at 35 days — may force him to close off certain portions of U.S. airspace as soon as next week, which will ground flights, ABC News reports.

Michael Alfonso, the son-in-law of Transportation Secretary Sean Duffy, is running for his father-in-law's old Northwoods congressional seat.

It’ll be a disaster in aviation,” Duffy exclaimed. “October is a slower, air travel month, and we have great weather in October.”

Transportation Secretary Sean Duffy warned that flights across the country could be delayed or even canceled due to the ongoing government shutdown.