On Tuesday the airline announced 2,600 cancellations, followed by 2,500 more for Wednesday and 1,400 on Thursday as the company sought to “reposition our people and planes.”

Southwest Airlines CEO Bob Jordan apologized for the disruption, admitting the company’s systems had failed in the face of “extreme circumstances.”

On Wednesday, Transportation Secretary Pete Buttigieg described the company’s problems as a “system failure,” during an appearance on ABC’s Good Morning America, and said it was “past the point” where the weather alone could be blamed.

Senator Elizabeth Warren blamed the “disaster” on the “consolidation in the airline industry,” which she claimed left customers with “fewer choices & higher prices.”

Speaking to Newsweek Jackie Freiberg, co-author of NUTS! Southwest Airlines’ Crazy Recipe for Business and Personal Success, suggested the company’s success at “managing costs rigorously” also left it with vulnerabilities.

She said: “While we don’t have first-hand knowledge on what exactly broke down, it appears that the company needed to upgrade a complicated, capital-intensive scheduling system. Culturally, operationally and technically, this is a huge undertaking. The disruption is not insignificant.

“When your success has been tied to managing costs rigorously, the challenge is, when do you bite the bullet and make these types of investments? It’s easy to vilify senior executives when a company is late to change, but these are difficult decisions to navigate. In this case, it appears that severe weather conditions revealed fault lines in a scheduling system that needed to change.”

Freiberg expressed confidence that the recent problems won’t be “terminal,” noting the company’s “tough-minded whatever-it-takes determination” to tackle its problems.

Karl Moore, an associate professor at McGill University’s Desautels Faculty of Management in Quebec, described Southwest Airlines as “one of the U.S.’ greatest airline stories,” noting its low-cost model had been emulated by companies across the world, including in Canada and Europe.

However, he told Newsweek, the company “truly fell short this last week or so.”

“Of course, winter weather was the trigger event. But winter storms are no surprise around Christmas…Other airlines suffered very much as well but Southwest, unfortunately, stood out,” Moore said.

“What reports from within Southwest suggest is that inadequate staffing caused by Southwest’s outdated employee scheduling system. It may well be that Southwest has relied too long on a system that very much needs to be brought up to date. Perhaps this is an area where Southwest has been too low cost in their spending.”

The professor said this week’s disruption is unlikely the “death knell” for Southwest, as the company is “too important a part of the U.S. airline industry,” but added the disruption will “hurt them for sure” and needs to be “fixed pronto.”

Professor Marc-David L. Seidel from the UBC Sauder School of Business at the University of British Columbia told Newsweek that Southwest Airlines’ “low-cost model” had left it with “very little buffer room” for problems.

“Historically, Southwest Airlines has always focused on a low-cost model that squeezes costs out of the system. When everything is operating smoothly this appears as very efficient, with quick turnaround times and low costs,” Seidel said.

“But the trade-off is that there is very little buffer room in the system to deal with unexpected events such as crew shortages, illnesses, extreme weather events, system-wide delays, etc. This is intensified by current tensions with labor and outdated IT and scheduling systems.

“In essence, these have all come together to create a non-stable system that will take a while to reset compared to other airlines that operate with more buffer in their systems and more modern scheduling systems.”

Seidel said the transport chaos “does not have to be terminal for Southwest,” echoing Moore’s argument.

To recover, he said the company needs to “update their systems, improve relationships with labor, build more buffer and redundancy into their overall system, and attempt to make things right for all those affected by this meltdown with sincere and significant customer service gestures.”

Speaking to Newsweek, a spokesperson for Southwest Airlines said the company had “available crews and aircraft” during the period but “our technology could not align our resources due to the magnitude and scale of the disruptions.”

A statement from the company said Southwest Airlines “plan to return to normal operations with minimal disruptions” on Friday.

Update 12/30/22 03:35 a.m. ET: This story has been updated with additional comment from Southwest Airlines and Jackie Freiberg.