It's not uncommon to see die cracks form at the base of the Memorial because it is so close to the edge of the die. A few years back, I was searching a $50 Mint bag of 1980 Phillies. When I spotted the first one with those die cracks, I set it aside. After finally searching all 5,000 coins, I realized that I had 11 rolls with those cracks. Chris
Very nice find. I've only ever found 2 with the four corner die crack. I personally think whenever you can find a quad crack it is a good find.