The Denver International Airport will work with Southwest, Frontier and United Airlines to review why thousands of Colorado flights were canceled or delayed over the Christmas holiday weekend.

Airport authorities announced Wednesday that it would conduct the reviews over the next two weeks. The reviews aim to uncover what happened, why it happened and how the airlines and airport will act differently to avoid the situation in the future.

“I believe it’s critically important that we seize the opportunity to learn from every incident,” airport CEO Phillip Washington said. “Though airline accountability is imperative for this latest event, we want to determine why flight disruptions and delays happened and how we can improve the overall operations here at DEN going forward for the good of our flying passengers.”

A winter storm hit Denver with extreme cold and snow last week, leading to the cancellation of over 1,000 flights and the delay of nearly 1,500 at the airport on Thursday and Friday – the busiest travel days of the year, according to data from Flight Aware. Though the storm has passed, issues have continued into the week, with over 900 Denver flights canceled or delayed on Tuesday and another 660 flights canceled or delayed as of 4:30 p.m. Wednesday. 

While mass cancellations affected several states over the holiday weekend, Denver International Airport suffered from the most cancellations of any airport in the country, USA Today reported. 

Due to the continuous flight disruptions, many people remain stranded in Denver with no way of reaching their destinations. On Monday night, an estimated 1,000 people slept on the airport floor and about 10,000 bags were left in the airport waiting to be processed, said the airport’s communications director, Alex Renteria. 

As Denver International Airport conducts its reviews, the airport has increased security around the baggage claim area and are providing blankets, diapers and other amenities to stranded passengers, Washington said.

In addition to the airport’s three major carriers – Southwest, Frontier and United Airlines – Washington said he encourages input from other airline partners and vendors for the reviews, as well.