I don't think so.... There is more to this than a is being told. I have been working in cable for 20 years. The max voltage on that line is 90VAC (actually 89.5, most are 60VAC) and never seen anything like this.
The best explanation is that maybe the person used a propane torch to shrink the heat shrink used to seal the fittings from the weather, and they started a small fire and did not realize it. Or maybe this poster's kids used one of those internet recipe fire bombs on it; I have dealt with exactly that 2 times before. I could not figure how every thing became so burned in those cases until I noticed the left over green plastic melted bottle residue.
Propane torch and a gas leak underground coming up in the pedestal. Maybe a primary electric line near the cable went and crossed to cable. Seen both.