Flooding the grave

When a grave is opened, the earth becomes loosed from its normally compressed state so that when the earth is replaced on top of and around the vault, it needs to be compacted to prevent uneven settling. To assist in this recompression process, the grave is flooded with water. This makes the dirt settle better around the vault. It freaked me out until I learned that the vaults are sealed air (and water) tight. It just sounds creepy.