Apparently there's a lot of variation in when a tire needs to be changed. What type of terrain you ride on for one. If you are always on smooth roads and seldom go through debris, your tires will last longer. The heavier the rider, the faster their tire will wear out. A guy friend of ours, who was tall and around 200 lbs had to replace tires quite frequently. He also learned he had been over inflating them.

I'm sure every tire manufacturer has their own recommendations, but dh guesses anywhere between 1,000 to 2,500 miles depending on what kind of tires you have and what you are putting them through. Some tires are built to last longer and resist flats, yet not necessarily built for speed.

It's quite possible you had run over something that was stuck in your tire, which could have caused your "explosion". Maybe a small nail or something. Dh replaced my tires recently when they weren't necessarily warn down, but had tons of little cracks in them from stuff I had ridden through. Each time you get a little crack, it makes the tire weaker. Also, any time you ride through glass, it's a good idea to stop and check your tires to make sure there are no pieces of glass stuck in them. Dh sometimes runs his hand (with glove) over each tire while he's actually riding to rub off anything that might be on them.

I think you DEFINITELY had a Bike Angel looking out for you! Funny. I actually have a necklace that has a bike with an angel standing next to it. My two friends and I bought them for ourselves, because a guy in our club started calling us his angels, like from Charlie's Angels, and we started calling him Bosley. You could probably find that necklace online if you wanted one.