Two people working at a Delta Air Lines maintenance facility near Hartsfield-Jackson Atlanta International Airport were killed and a third was seriously injured in an accident early Tuesday morning, according to a statement issued by Delta.

The accident happened in the wheel and brake shop at the airline’s Atlanta Technical Operations Maintenance facility, the statement said. The statement did not specify the nature of the accident, but confirmed the victims were Delta team members.

“We are extending our full support to their families at this difficult time and conducting an investigation to determine what happened,” the company said in an email Tuesday afternoon.

A spokesman for the airport directed questions to the airline, which said the cause of the accident is under investigation. Travel was not disrupted after the episode on Tuesday morning, the airport said. Delta said that the maintenance facility remained open.

The Atlanta Police Department referred questions to the airline and the Atlanta Fire Rescue Department did not immediately respond to emails or calls seeking comment. The two people who died were not identified and the status of the person who was injured was not immediately clear.

The Federal Aviation Administration said it was aware of the accident but directed questions to Delta. The International Association of Machinists and Aerospace Workers, which represents airline workers across North America, called for Delta and the authorities “to quickly launch a thorough investigation” into how it happened.

In a social media post, Mayor Andre Dickens of Atlanta offered his “deepest condolences to the family and loved ones of the deceased Delta employees.” The fire department, police department and airport teams were working to address the situation, he added.