WHAT happened to my tire? mystery gash.

[jonismyname]

up at 4, on my way to work at 5. drove about 20 miles to work. didn't notice any problem, but the radio was up. here it is 730 and i have a flat. cars been sitting in a parking lot for 2 hours by itself, in plain view of main road and someone would have to drive by my office to get to the lot/car.

there's a 3" gash going up the sidewall starting about half way and going out to the tread. it looks rather clean, and there's two thin nylon white cords that are visible that appear to be rather clean, but frayed.

there's some sign of sidewall damage, just a bit of wrinkling and crinkling.

my commute includes a sweeping 180 degree highway ramp that i took fairly fast this morning, didn't notice any wandering or un-settled ness. the flat would've been outside rear. the rim has absolutely no damage.

could i have driven on a soft tire losing air and had the split occur randomly or naturally? could one of my neighbors slashed my tire and i drove to work on it without noticing and without damaging the rim? if someone had slashed it while i was at work, i would'nt have any damage on sidewall from driving? where parked currently, slash was at 12oclock, so not like it was sitting on that part of the sidewall... these tires have an adventurous history, as i bought them from whoppeee (if you're out there, any insight?) and had to put a boot in the front tire for a small shallow gash that was slowly leaking. that one was there when i bought the wheels/tires, but this one was not.

any insight is appreciated as im stumped. i'll have it replaced before i leave work today, but im entirely perplexed as to what happened and don't know if i should sit in the woods next to my car tonight with my hickory stick.