Stacking caskets and bodies in cemeteries has been practiced for decades if not centuries. Many modern urban cemeteries have done it since the 19th century and almost all do it today. The Potter's Field that NYC runs on Hart's Island and has run since 1869 holds over a million burials and counting and they stack them three high. And then after a credible passage of time, they start over again. Kelvin Kean Elverson, Pennsylvania