Airports in multiple U.S. cities have reportedly been impacted by staffing shortages of air traffic controllers. Denver, Phoenix, and Newark are among the cities impacted by ATC facilities experiencing staffing issues. The staffing shortages caused flight delays and cancellations across the country. A week into the government shutdown, air traffic controller sick calls are beginning to cause delays and cancellations, as a number of airport towers and control facilities lack the staff to properly handle flights. https://t.co/i2wnNzoEBA — World News Tonight (@ABCWorldNews) October 7, 2025 More from ABC News: Controllers are considered essential workers and are exempt from being furloughed during a shutdown. An estimated 13,294 controllers will continue to work without pay during the shutdown, according to the Department of Transportation’s shutdown plan. California’s Burbank Airport was hit hardest Monday and was forced to close its tower from 4:15 p.m. through 10 p.m. PDT because it had no air traffic controllers, according to FAA documents. The airport remained open but flights were delayed on average more than 2.5 hours. Controllers from a San Diego facility handled traffic into and out of Burbank during the tower closure. “Clearance is closed. Ground’s closed. Local’s closed. The tower is closed due to staffing. You just contact SoCal on the 1-800 number in the green book for your clearance,” a controller can be heard informing pilots on air traffic control recordings, referring to a published listing of airport information. Several other ATC facilities also experienced staffing issues on Monday. The Philadelphia TRACON (Terminal Radar Approach Control), Denver Center, Detroit TRACON, Indianapolis Center, Phoenix Airport, and the Phoenix TRACON also had staffing advisories from the Federal Aviation Administration. More than 600 flights Monday were delayed in and out of the Denver Airport and over 200 at Phoenix Airport. “US airspace as of 17:30 local (21:30 UTC) — multiple air traffic control facilities have staffing shortfalls this evening, including Chicago, Nashville, and multiple facilities in Texas and the northeast,” Flightradar24 stated. US airspace as of 17:30 local (21:30 UTC) — multiple air traffic control facilities have staffing shortfalls this evening, including Chicago, Nashville, and multiple facilities in Texas and the northeast. pic.twitter.com/oRdE4r3e8V — Flightradar24 (@flightradar24) October 7, 2025 “There have been increased staffing shortages across the system. When that happens, the FAA slows traffic into some airports to ensure safe operations,” the FAA said in a statement to ABC News. “Air traffic controllers, who are already working 6 days a week, are now telling me they may have to find a second job to pay their mortgage because of the shutdown,” Transportation Secretary Sean Duffy commented. “All because @SenSchumer and @RepJeffries want to play politics,” he added. Air traffic controllers, who are already working 6 days a week, are now telling me they may have to find a second job to pay their mortgage because of the shutdown. All because @SenSchumer and @RepJeffries want to play politics. pic.twitter.com/YZ85p0od6q — Secretary Sean Duffy (@SecDuffy) October 7, 2025 CBS News provided further info: On Monday, a total of almost 6,000 flights were delayed in the U.S., including 42% of flights leaving from Chicago’s O’Hare International Airport and 23% of those from Hollywood Burbank according to tracking site FlightAware. Weather issues also caused some flight delays on Monday. As of Tuesday morning at 9 a.m. EDT, more than 600 flights within the U.S. had been delayed, FlightAware data shows. The National Air Traffic Controllers Association (NATCA), the union representing the nation’s air traffic controllers, on Monday instructed its members to keep working during the government shutdown. Because air traffic controllers are classified as essential workers, they’re expected to continue working without pay, although they would receive back pay once the shutdown ends. “It is normal for a few air traffic controllers to call in sick on any given day, and this is the latest example of how fragile our aviation system is in the midst of a national shortage of these critical safety professionals,” NATCA said in statement. It added, “NATCA has consistently warned that the controller staffing shortage leaves the system vulnerable, and today’s events underscore the urgent need to accelerate training and hiring.” The TSA has seen a slight increase in air traffic controllers calling in sick since the shutdown began last week, Transportation Secretary Sean Duffy said Monday at a news conference at Newark Liberty International Airport in New Jersey.