If an earthquake-God forbid-took place in a certain area, resulting in a large number of deaths, and there was a dire need for digging mass graves, what is the ruling of Sharia on such graves knowing that people of different faiths are buried together? In addition, what is the ruling on not burying the dead in this case?

What is the manner for shrouding the deceased?

How should the deceased be washed, shrouded, and buried?