WASHINGTON, DC – Southwest Airlines executives were on the hot seat Thursday, facing criticism from senators at a hearing on Capitol Hill.

“So why did this happen? Let me be clear. We messed up,” Southwest Airlines Chief Operating Officer Andrew Watterson said.

Watterson didn’t mince words, blaming the airline for all the trouble.

“I want to sincerely and humbly apologize to those impacted by the disruption,” he said.

Watterson told the Senate Commerce Committee that failures with Southwest’s systems and infrastructure during the winter storm crippled the airline, leading to a cascade of more than 16,000 flight cancellations.

“Ultimately, none of this is an excuse,” he said. “We need to make sure our operation resiliency and technology are strengthened for future extreme weather events, no matter how unprecedented.”

“Good service costs money and bad service saves money,” said Paul Hudson, president of Flyers’ Rights, the largest airline passenger advocacy organization.

“Because US airlines are not required to pay delay compensation for domestic flights, unlike for international air travel, Southwest avoided more than half-a-billion dollars in delay expenses.”

Illinois Senator Tammy Duckworth was among the lawmakers questioning Southwest executives, saying, “We must crack down on carriers that have gotten away with predatory practices that treat customers like suckers and view passengers with disabilities as disposable.”

Watterson told the committee that fixes to the scheduling system that caused December’s failure will go live Friday, as the airline continues to reimburse passenger claims and return lost bags.

“We’re intensely focused on reducing the risk of repeating the operational disruption we had in December and repairing the trust our company’s had and earned over our 52-year history,” he said.