Questions about burials

I understand that some people wait while the grave is filled in. Why is this?

Some cultures require that the grave is filled in while the family watch or they may wish to undertake the backfilling of the grave themselves. When families want this, it is essential that the cemetery is made aware of their requirements when the burial is first arranged. This will ensure that the family's wishes are met and that their safety is protected during the backfilling process.