Tire Tread/belt problems of the 2003 Honda Civic

I have a 2001 Honda Civic that has firestone p185/65xfr690 tires onit. I had check my tire pressure before leaving for work. All was fine. About 7 miles into my 9 mile drive to work my car acted like a big gust of wind had just hit the front. I pulled over to check out the car. I discouvered that the 2 left tires were low. By the time I got to work the front had gone flat. When I change it with the spare I discovered that the tread had separated from the tire at the inner side wall. I then crawled under my car to examine the other low tire to find it had separated also. When I arrived at the tire store to have all 4 replace atleast one of the other 2 was also showing signs of separation. I retained the tires from the dealer and have them at mey home in aurora.