Two workers were killed and one was seriously injured at Delta Air Lines’ maintenance facility at Hartsfield–Jackson Atlanta International Airport, according to Delta TechOps and first responders. Authorities called the incident a “possible explosion.”

Delta TechOps said the accident occurred Tuesday morning at its wheel and brake shop.

When emergency responders arrived at the “possible explosion,” they found “three Delta employees on the ground” and paramedics said they were attempting to stop “heavy bleeding,” according to the Atlanta Fire Department’s incident report.

An employee reported hearing an explosion and seeing workers fleeing, the incident report states.

“I realized they were running to get help. I walked toward the explosion site and saw a body lying face down, not moving, with blood everywhere,” the worker told officials, according to the accident report.

Delta said the accident involved a tire and parts of the tire. The wheel was not attached to or near an aircraft at the time of the accident, Delta said.

According to investigators, the wheels were “removed for maintenance purposes” and not attached to an aircraft.

According to airport authorities, the incident had no impact on airport operations.

The U.S. Occupational Safety and Health Administration said it had launched an investigation.

Delta said it was “working with local authorities and conducting a full investigation to determine what happened.”

The airline added that it was “heartbroken” and “grateful for the rapid response of first responders and medical teams on site.”

The workers killed in the incident were identified as Mirko Marweg, 58, and Luis Aldarondo, 37, according to the Clayton County Medical Examiner’s Office. The third employee, whose identity has not yet been released, is still hospitalized, officials said.

“We fully support their families during this difficult time and are conducting an investigation to determine what happened,” John Laughter, executive vice president, chief of operations and president of Delta TechOps, said in a statement. “This news is heartbreaking for all of us.” (Employee Assistance Program) Resources will be on site at the (Atlanta Technical Operations Maintenance Facility) to support our teams for as long as necessary.”

Atlanta Mayor Andre Dickens said: “I would like to express my deepest condolences to the families and loved ones of the deceased Delta employees. My thoughts are also with those injured and I hope for their speedy and full recovery.”

Representatives from Atlanta Airport also expressed their condolences.

ABC News’ Sam Sweeney contributed to this report.