At least I'm not totally alone here...
I think it is quite possible as mentioned for an "Ordinary" 120 drop on the POCO side of a main breaker to do just this type of damage. No 'freak of nature' or high voltage... Just 120 at several thousand amps vaporizing a very narrow path to ground in a microsecond... (A ball of super-heated metalic gas) Admittedly the scenario is strange, but not so far out there, IMO. There a lot we don't know about the incident, but having seen a POCO side short at 120 up close remove roughly 9 square inches of 14g steel in a simular explosive detonation, I'm gonna pull a 'mythbuster - plausable' on it. And not that I would suggest anyone try this at home.... (Without proper PPE and notification/participation of your local POCO) I don't think the RG-6 impedance would make any noticable at all at with that amount of energy.
