Modifying a 32# cannonball doesn't necessarily make it a land mine. The important part in the picture can barely be seen. This "what ever" should have been defused and studied by someone that knew what they were really looking at. At least better pictures should have been made of it. This being fresh out of the ground after 150 years was in no chance of exploding, now if it had sat on a fireplace hearth for a few years, yes I would be worried. You can bet that the only thing that exploded in this debacle was the C4, and also you can bet that "they" want look for any of pieces to prove that fact. I'm sure "they" may think it is still dangerous. There is a safe and easy procedure to defusing anything like this, you would think with all the training that a bomb squad would go through. They would have gone through Defusing 101. If your going to mess with Civil War, you should know Civil War.