My Fourth of July ended on rather a downer note. As I was driving home from Dustin and Jess's place after midnight, I suddenly heard a loud hissing followed immediately by the unmistakable slapping of rubber against concrete at high speed. I pulled off the road as soon as I found a suitable spot, and confirmed that one of my tires was totally flat. I changed it out as fast as I could (since I have an almost worthless jack, it took forever), then went on home, planning to deal with it later, when Discount Tire was open on Monday.
I drove the Ragged Tiger on up to Discount Tire's N. May location this morning, and to my amazement, they presented me with this:

The cause of my flat