general problems of the 2005 Ford Thunderbird

While driving my car on the highway last evening, the left shoulder airbag was deployed. I immediately pulled the car to the side of the road. I noted that the left front tire was flat. My husband changed the tire. Upon removing the wheel we noted that the tire was completely normal, but the rim was fractured on the internal aspect. The seat was damaged from the deployed airbag. It appears that the rim implosion set off the left shoulder airbag. Had it been the chest airbag, I would have had an accident. I called the local dealer and they told me that they have never heard of this. I had 4 new tires placed about 1 month ago at costco in albuquerque. The car has only 16,000 miles on it. I have owned it for theee years. Prior owner an elderly man- drive it 10,000 miles over 13 years. I am not aware of ever any damage to the wheel or hitting anything with it. I was driving 60 mph when this occurred. I have included a picture of the inside of the tire rim.