Travelers can breathe a sigh of relief after a weekend of canceled flights.

Over 15000 flights have been canceled or delayed in the US since the start of the July 4th holiday. There were about 1,250 flights that were canceled and another 15,400 that were delayed.

American Airlines and Delta Air Lines canceled about 250 flights each, accounting for 3% of their schedule. About 2% of United Airlines' flights were canceled.

Despite the chaos, US airlines are getting back on track, with United, American, and Delta all canceling flights on Monday at the time of publication.

On Sunday, 51, 28, and 54 flights were canceled, as well as 43, 104, and 81 flights on Saturday. At the time of publication, Southwest Airlines had canceled six flights.

According to CNN, bad weather and staffing shortages are to blame for the chaos, but a former airline pilot said pilot and air traffic control staffing are the most important factor.

She told CNN that the weather this summer hasn't been worse than usual. It takes airlines more time to scramble and recover when there is a severe weather event. There is no deep bench of pilots to call in. It seems like it's more of a systemwide staffing issue that's trickled down to the FAA.

There are days when ATC staffing at the Newark Liberty International Airport hub is less than 50% according to Scott Kirby.

Insider has learned that the FAA does not have a system-wide air traffic controller shortage, but has placed more controllers in Florida to support the increased travel demand.

Airlines for American said the Jacksonville Air Route Traffic Control Center has been understaffed for 27 days in a row.

A4A called on transportation secretary Pete Buttigieg to address the staffing issues ahead of the July 4 holiday, saying the shortages have led to traffic restrictions under blue-sky conditions.

If operations aren't improved, airlines will be punished. The senator called on the cabinet member to fine the carriers $55,000 per passenger for every flight cancellation.

The last three holiday weekends have been busy for US carriers, with 3% of flights canceled over Memorial Day and 4% canceled over Juneteenth. More than 1% of flights were canceled in the year.

Henry Harteveldt told Insider that the situation was not expected to improve.

He said that the system does not bend when there is a problem. It just snapped.