Tire failure heads up

[RVGRINGO]

We blew a Continental rear tire on our Smart at 70 MPH in a tunnel going under the river at Mobile, Alabama, after passing through a construction zone. We had probably punctured the tire, which then deflated, got hot and the sidewalls just exploded. We saw the tire pass us and we felt nothing! Amazingly, there was no sound of metal on pavement and we didn't dare stop in the tunnel. So, we exited slowly over a very long flyway into Mobile and parked. Fortunately, the tire's bead remained on both sides of the rim, protecting it. We had thought we might experience a long vacation in Mobile while we waited for a tire and rim from Mexico, Europe or Canada. We had a flatbed ride to a large tire merchant and he found us a Bridgestone just a bit wider (185) and we were soon on our way. Later, back home in Mexico, we managed to find a matching Bridgestone and now have the other Continental in the closet; just in case. If we plan another 5000 mile trip, we may buy a front rim and tire to carry with us as a spare. Ours is a 2007, 450, and we don't have pressure sensors.

[jwight]

Thanks for all the comments. To address a few, the tire did not "blow out." It was at full pressure when it was changed for the spare and there is no hole or cut on the inside of the tire. Not an el cheapo tire but not one of the big name brands either; it is a Futura Plus Touring tire sold by a lot of places, and regularly rotated. And last, the tire was not worn to the wear bar as you can see (and was pointed out by Dave) in the photos. I'm still betting on an internal belt failure.

[GASHOG]

While this likely has no bearing on smart tires because they are so relatively new, learn to read the date code found on the inside of your tire.

They should have, if made after 2000, a four number code. The first two numbers are the week of the year in which the tire was made, and the last two numbers are the year. If you buy tires, make absolutely certain that they are no more than 6 months old by the date code and check each tire! If its a 3 digit code, then the tires are at least 9 years old if not more! Old tires fail. Under-inflated tires fail as correctly pointed out. In this day and age of fuel concern, checking tire pressures is something that every person can do but virtually NONE ever do. Your life might depend on it so learn to check these things.
Here's how to read the code:
ABC News

Here's how ignoring that code can kill you:
20/20 News report on tire failure deaths