Above is not safe
Below is safe
Help restore history!
Have you ever visited a cemetery and have seen leaning, buried, and headstones that are just not safe? Monuments - tombstones - headstones that are upright, usually have at least two sections or more. The sections are connected with a compound that creates a suction and seal when the top section is set on the stone underneath. Throughout the years, this seal becomes weak and also deteriorates and crumbles. Way back in the 1800's to the early 1900's foundations were really not made very well. They used field rock, bricks, sand, other types of rock and maybe concrete in the mix. As you most likely guessed, these foundations shift throughout the years, making the monument lean. In order to fix the leaning problem, the old foundation needs to be removed and a new foundation installed. This is the only way to solve this problem and don't let anyone tell you different.
Of course we could jack up the monument and wedge a rock underneath, but this is something we do not do and is just a bandage. The problem is there, underneath the ground. This is a very serious problem in the majority of cemetery around the United States.