Today no one is buried alive, but a 150 years ago that wasn't so true. I don't know exact numbers, but I do know it was a real fear people had. There were caskets sold with bells attached so if they were buried they could ring a bell above ground. Edgar Allen Poe was so afraid of this he had a special casket made and left instructions with people about what to do.
The Answer To that Question Is Two.
There are 3000+ people buried in Westminster Abbey.
when they die, they thought they would still be alive in the afterlife
Three
You can't dig a hole that deep at a beach. When you hit the water table, the hole will collapse. Many people died that way. And you can get buried alive.
2 people are still alive
I was there a week ago and asked a guide. He said that there are about 400000 graves, then there are memorials, some even for thousands of soldiers. An average of 25-30 graves is added each day.
Just one.
Positives were that he started to build the great wall of china to protect from northern invasions but many people perished doing so under his harsh treatment and when people spoke out against him he buried them alive.
There is no way to know. Many people were buried in unmarked graves.
Usually 6 feet under.
There are three.