Spare Tire problems of the 1998 Ford Mustang

My rt. Front tire blew while I was traveling. Even though I was going slow, there was enough force to take out a peice of my wheel cover & dent the front door. I had to replace it at t little tire store in the town it happened in. I replaced all the tires at the same time because the shop worker showed me a place on the left front tire that looked like it was separating too. At the time, I thought that a big-brand name like firestone shouldn't do that, so I replace it with another brand. I realized that if it had happened on the open highway at a high speed, I could have lost control of the car & I felt lucky. But it was costly & I still have the dent & peice if fender in my floorboard. I do not have the tires so I do not know any particulars about them, but the dealer should. I probably can get the tow service to attest to the fact that it did blow, he put on one of those little temporary tires & suggested a few shops I could try to get a tire at. (tiresize: 15)( dot number: tire size: 15 ).