10:57 AM EDT, 07/22/2024 (MT Newswires) -- Delta Air Lines ( DAL ) cancellations continued to mount on Monday as the carrier worked to recover from Friday's tech outage that disrupted IT systems around the world.

The company's cancellations reached 703 by Monday morning, bringing its total cancellations since the outage to just above 4,500, according to data from FlightAware. Delta's shares fell 1.8% in Monday trade.

"Like many companies worldwide, Delta was impacted on Friday morning by an outside vendor technology issue, which prompted us to pause flying while our systems were offline," Chief Executive Ed Bastian said in a Sunday message to customers.

Delta has a "significant number" of applications that use the Microsoft (MSFT) Windows operating system that was impacted by the CrowdStrike ( CRWD ) system update, he said. One of its crew tracking-related tools was particularly affected.

The pause in operations resulted in more than 3,500 Delta and Delta Connection flight cancellations through Saturday, according to Bastian. Cancellations continued on Sunday, he said.

"The technology issue occurred on the busiest travel weekend of the summer, with our booked loads exceeding 90%, limiting our reaccommodation capabilities," Bastian wrote. "I want to apologize to every one of you who have been impacted by these events."

Delta has been the most impacted carrier by far, data from FlightAware showed. United Airlines (UAL) canceled a total of 1,407 flights from Friday to Sunday and an additional 17 by Monday morning. American Airlines ( AAL ) canceled 593 flights from Friday through Monday morning, according to FlightAware.

Shares of Crowdstrike ( CRWD ) plunged 11% intraday Monday following a similar drop on Friday. Oppenheimer removed the cybersecurity company from its top picks on Monday and said it expects shares to face ongoing near-term pressure from what has been billed as the largest IT outage in history.

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