Los Angeles, Jul 23 (IANS): The global tech outage continued to wreak havoc on US air travel Monday with hundreds of flights cancelled and thousands of passengers stranded at airports across the nation, four days after the incident caused widespread flight cancellations and delays.

According to data from the flight tracking site FlightAware, 1,759 flights within, into or out of the United States were cancelled, and over 10,000 were delayed on Monday.

Delta Air Lines was particularly hard hit, with 1,152 flights canceled and 1,725 flights delayed on Monday. Delta has cancelled over 5,000 flights since the outage began in the early hours of Friday.

The airline's CEO, Ed Bastian, has apologised for the disruptions and announced that Delta is offering reimbursements to affected customers, Xinhua news agency reported.

Bastian expected the flight disruptions to last for "another couple of days" as the airline is "working around the clock" to restore normal operations.

Other major carriers, such as United Airlines, American Airlines, and Southwest Airlines, have gradually recovered from the initial shock on Monday.

Bastian said that the disproportionate impact on Delta is attributed to the outage affecting the airline's ability to track its crews and process changes, leading to a cascading effect of cancellations and delays.

Hartsfield-Jackson Atlanta International Airport, Delta's primary hub, was the epicenter of the chaos, where thousands of passengers faced long lines and extended waits. The airport has seen over 500 flight cancellations and nearly 1,200 delays on Monday, according to FlightAware.

The impact of the outage was being felt across the country. At Harry Reid International Airport in Las Vegas, Nevada, the situation is still challenging, while 53 flights were cancelled and 559 flights delayed Monday, according to FlightAware.

In Colorado, Denver International Airport saw nearly 600 flights delayed and 50 cancelled on Monday. The situation was further complicated by thunderstorms in the area, with arriving flights delayed by an average of 40 minutes.

Other major airports across the country are experiencing varying degrees of disruption, with most facing minor delays.

Passengers were advised to check their flight status frequently and be prepared for potential changes to their travel plans.

This prolonged recovery period is causing frustration among travelers and raising questions about the resilience of airline IT systems.

Industry experts said that as airlines increasingly rely on sophisticated IT systems to operate, the potential for widespread disruption from a single point of failure became more pronounced, calling for improved resilience and backup systems to prevent similar large-scale disruptions in the future.