We had one cherry tree that grew into four trunks and shot up all tall and spindly. I wanted to cut it down way back when I could have done it by just using a stepladder, but I let it grow for the shade. It was nice sitting out under that tree in the summer, but one trunk grew out at a steep angle. I was afraid it was going to come down in a storm, so I had a tree service in Long Island come out to just cut the one trunk and maybe prune back the other parts of the tree.
The problem is that when they started cutting the one trunk, they found a lot of inner rot. The wood in the center of the tree was nonexistent. Only the outer layers remained. There was very little structural integrity to the tree, and none of us could figure out how it did not break sooner. A couple of core samples showed that the other trunks were hollowed out too. We had them take down the entire tree and pull the stump. We wanted the stump gone right away so we could plant a new tree in that spot. If the stump was just ground down, it would not let us be able to dig to plant a new tree there.
There was one section of the tree where the cross-section of the tree was intact. It was not very much. I kept a log and had it cut and had a slice of it made into a clock to commemorate all the time we have spent outside under that tree in the summertime. And to remember how it could have fallen at any time but did not. We were sad to see the tree go, but we had a happy moment when we planted the new tree together.