Small triangular piece of glass, penetrated the thickest part of the tread at roughly the center of the tire. Tube was pierced such that it would go soft after a mile, not right away. Maybe sealant would have stopped that.
I'm surprised, I probably picked enough glass out of my Gators to make a six-pack but they never made it through. Guess I didn't meet the right piece of glass. Not that it would have made a difference but what tubes do you use?