Travelers frustrated on 5th day of Delta cancellations at PHL after tech outage

PHILADELPHIA (CBS) – Delta Airlines canceled more flights at Philadelphia International Airport on Tuesday as it struggles to recover from Friday's CrowdStrike outage. This comes as other airlines are bouncing back and returning to normal operations.

The process of getting the flight schedule back on track is "deeply complex," Delta said. More than half of the carrier's systems worldwide are based on Microsoft Windows. IT staff has to manually reboot each system and wait for applications to synchronize.

Since Friday, Delta has canceled more than 5,000 flights worldwide and delayed hundreds of other flights. Passengers like Sydney Wilson from Warner Robins, Georgia, were left stranded. Her flight from Philadelphia to Atlanta was supposed to leave on Sunday but was canceled because of the software outage.

"[I am] very frustrated," Wilson said while waiting at Delta's terminal at PHL. "I missed work yesterday and today. Initially, they said they weren't going to pay for our hotel accommodations. We had to pay for our own rental to get to the hotel."

Heather Redfern, a spokesperson for Philadelphia International Airport, said Delta hubs like Atlanta, Minneapolis and Boston fared worse than Philadelphia.

"Our cancellations and delays for Delta have gone down significantly day by day, so hopefully people are getting to where they need to go," Redfern said.

On Tuesday, there were 30 cancellations and more than 100 delays on all airlines at PHL.

Jennifer Dellmuth from Minnetonka, Minnesota, said the tech fiasco highlights the need for safeguards to prevent future travel disruptions.

"I think we need to focus on our infrastructure," Dellmuth said as she checked in for her flight at PHL. "It's going to happen a lot more. We don't put enough investment in infrastructure."

Delta said it is trying to make things right by allowing customers to change their itinerary for free. The airline is also allowing customers to apply for a refund if they decide to cancel a portion of their trip.

The U.S. Department of Transportation has opened an investigation into Delta's slow recovery after numerous complaints about the carrier's customer service.