Microsoft cloud outage causes airlines to ground flights

Microsoft said on Thursday it was investigating issues with its cloud services in the Central U.S. region, which had caused the grounding and cancellation of several flights.

Low-cost carriers Frontier Airlines, a unit of Frontier Group Holdings, Allegiant and SunCountry reported outages that affected operations.

While Frontier said a “major Microsoft technical outage” had hit its operations temporarily, SunCountry said a third-party vendor affected its booking and check-in facilities, without naming the company.

“The Allegiant website is currently unavailable due to the Microsoft Azure issue,” Nevada-based Allegiant said in a statement to CNN. Allegiant did not immediately respond to Reuters request for a comment.

Frontier cancelled 147 flights on Thursday and delayed 212 others, according to data tracker FlightAware. 45% of Allegiant aircrafts were delayed, while Sun Country delayed 23% flights, the data showed. The companies did not give details on the number of flights impacted.