Proximate cause: Failure of the pilot to evacuate on the runway at wheel-stop.
I can't wait to find out why he/she was prompted to roll to the gate while under confirmed fire emergency.
Alright. It seems the early report by CBS (below) that I saw was egregiously in error.
https://www.youtube.com/watch?v=h5vGO654pcI&t=24s
The plane was diverted due to engine vibration, not fire, landed without incident and taxied before smoke then fire.
Gotta love these asshat ‘journalists’...