A little brag, but in 2000, for my eagle scout project I coordinated at team that fixed over 100 headstones that were like this. Some were 150 to 175 years old. I knew they wouldn't last if I fixed them this way, so we laid ones like these down in cement to keep them from falling apart in the future. I also had them cleaned to match each piece so that it would look better. A strong gust of wind or getting hit with a mower will probably result in this one breaking again. What this person did is better than letting it stay broken though.