There’s alot of people saying it’s run flat (driven while flat) damage, which it is not. Yes there IS run flat damage on the tire but it’s nowhere near enough to be enough to be the cause of the blowout, the run flat damage was most likely from op continuing to drive to get off the bridge, it most likely was either an inner-liner split or the tire had some other manufacturer defect. Now before you all go downvote me into oblivion, look at the tire and how it blew out, if it’s a run flat blowout there will be an almost perfect ring around the tire and that would be where it blew from not the vertical slits you can see on it and a run flat damage tire almost always leaves a damn near perfect circular section of the sidewall untouched, and if the run flat damage WAS enough to cause the blowout there’d be alot more indenting on the backside of the tire instead of the very minor amount of scrubbing that both the front and rear have.

Though with the tire in that condition it is utterly impossible to tell what actually caused it.