August 9, 2021: CEO Ted Christie said that the causes of Spirit Airlines’ massive flight cancellations that derailed the summer vacations of tens of thousands of customers in this week have brewed for above a month.

The delayed flights in July, staffing shortages, technology problems, and an increase in travel that has taken most airline executives by surprise culminated with over 1,700 flights canceled since Sunday, some days accounting for more than half of Spirit’s schedule.

And the trouble isn’t over for travelers. Christie said the carrier needs to cancel additional flights for the coming several days to regain its footing.

“There are some angry people,” he told reporters on Thursday. “Right now, all I can say is we’re very sorry for what happened.”

The chaos enraged stranded customers in the airports and sparked furious messages online, presenting Christie with one of his most extensive tests since he became CEO on New Year’s Day 2019.

He said that chronic delays in July snowballed, which led to staffing shortages as crews timed out, which reached the maximum time they could legally work each day. It became worse on the weekend and on the days after that.

“We couldn’t get in front of it,” Christie said. He added that “tens or hundreds of thousands” of customers were affected by disruptions of Spirit and estimated that it is too early to assess financial impact to the company.

According to flight-tracking site FlightAware, more than 230 flights or a third of its schedule was canceled on Friday. On Thursday, 446 Spirit flights were canceled, 56% of its operation.

A sharp rebound in summer travel has created headaches for summer travelers as airlines and their contractors are facing staffing shortages coupled with the usual disruptive summer storms. American Airlines had a cascade of cancellations earlier this week triggered by severe thunderstorms that hit its Dallas/Fort Worth International Hub and subsequent staffing shortages.

“We are going to do everything we can to earn back the confidence of our guests and the traveling public. We believe we can do that,” Christie said on the call Thursday. He said the airline is giving customers affected cash refunds.

Last month, the airline forecast it would fly nearly 11% more in the third quarter in comparison with the same period of 2019, a much more significant rebound than other airlines.

Christie said he and other executives are examining how to add backup staffing, faster responses to operational hiccups, and better technology.