On Monday, thousands were left stranded in airports after two of the largest airlines in the United States cancelled or delayed over one thousand flights.
American Airlines canceled 562 flights on Monday, which was 18 percent of their total departures for the day, according to Flight Aware.
In addition, 1050 flights were delayed by the airline, representing 35 percent of their total departures. In total, more than half of American Airlines' flights that day were delayed or cancelled.
Budget airline company Spirit Airlines cancelled 334 of their flights Monday, which was 42 percent of their Monday departures, and delayed 235, or 29 percent of their departures.
According to the Daily Mail, two large Florida airports were hit hard, with 40 per cent of Orlando's flights and 37 per cent of Fort Lauderdale's being canceled or delayed on Monday.
As the demand for air travel ramps up again, airlines are struggling to keep up with the demand with smaller staff numbers and inclement weather instances.
According to the Transportation Security Administration, more than 2.2 million people went through airport checkpoints on Sunday, marking the highest number since February 28, 2020.
Sunday was plagued with delays and cancellations as well, with 7,400 US flights being delayed at least 15 minutes, and more than 900 canceled, according to Flight Aware.
Nearly half of Sunday's cancellations were at Dallas/Fort Worth International Airport, which is American's largest hub. It was reportedly hit with numerous afternoon and evening thunderstorms, grounding flights.
The delays and reported staffing issues has some questioning where the $54 billion in taxpayer money received to keep employees on airlines' payrolls during the pandemic went.
Chair of the Senate Commerce Committee Senator Maria Cantwell questioned key airlines on why the worker shortages have occurred.
"I am deeply concerned by recent reports highlighting… workforce shortages that have caused flight cancellations and generated delays for passengers," wrote Cantwell in a letter addressed to the CEOs of American Airlines, Delta Air Lines, JetBlue Airways, Southwest Airlines, Republic Airways, and Allegiant Airlines on July 16.
"These shortages come in the wake of unprecedented federal funding that Congress appropriated, at the airlines' request, to support the airline industry during the COVID-19 pandemic," she continued
"As passenger travel has boomed in recent weeks, new reports also suggest that some airlines are now unprepared to meet the increased demand that they scheduled for, and have resorted to delaying or canceling flights," Cantwell added.
Cantwell reportedly asked "each airline to account for its utilization of federal funds and provide further information on current and projected workforce shortages," according to the Daily Mail.
Stranded passengers took to Twitter to highlight their experiences at airports across the country and around the world, with some being stranded without their luggage, and flight agents leaving their posts with police escorts.