The Amazon cargo plane struck several vehicles amid its failed landing.

A tragic twist has emerged in the deadly UPS cargo plane crash in the United States, with reports the three crew members killed were meant to be flying on a different aircraft before a last-minute switch.

The grim task of finding and identifying victims from the firestorm that followed a UPS cargo plane crash in Louisville, Kentucky, entered a third day Thursday as investigators gathered information to determine why the aircraft caught fire and lost an engine on takeoff.