At 11:26 Orange County Fire Authority received reports of alarm activation in one of the terminals at the airport. When crews arrived on scene they were told that a tire from the plane had unexpectedly exploded and caused an employee in the area of the tire to suffer a heart attack. He was immediately rendered aid but had expired before being transported to the hospital. It is unclear the reason the tire exploded or what the employee was doing in that area of the plane. The OC Sheriff is on scene investigating.