Two workers were killed and a third was seriously injured when a tire exploded early Tuesday in a Delta Air Lines maintenance hangar near Atlanta’s Hartsfield-Jackson International Airport. Officials said the aircraft tire exploded while it was being changed. USA Today Sources told WSB-TV that a Delta employee and a contractor were killed and a second Delta employee was hospitalized with serious injuries. Airport operations were not affected by the accident, which occurred around 5 a.m.

The facility where the accident occurred is part of Delta TechOps, which performs maintenance and repair work for Delta and more than 150 other customers, the AP reports. “The Delta family is heartbroken over the loss of two team members and the injury of another following an incident this morning at the Atlanta Technical Operations Maintenance (TOC 3) facility,” the airline said in a statement. The tire was on board a plane that arrived in Atlanta from Las Vegas on Sunday evening, according to WSB-TV.

John Laughter, operations manager and president of Delta TechOps, told employees that the accident occurred in the plant’s wheel and brake shop. “We fully support their families during this difficult time and are conducting an investigation to find out what happened,” he said in a message to employees shared by USA Today. “This news is heartbreaking for all of us.” (More stories from Delta Air Lines.)