What happens to a mortgage when a person dies intestate with no life insurance to cover the outstanding debt. Does the account get frozen or does it continue to accrue interest

There are quite a number of points to be covered to answer your question:-

1) The account gets frozen.
2) No further interest is charged.
3) The bank usually holds the deeds to the property.
4) They usually foreclose.
5) The bank then sells the property and recover what is owing.
6) Any balance of moneys go to the estate.

The loan is not frozen. At least not until the lender receives notice of the death of the loan holder.

If there is no heir, then this may not happen for a while. When payments stop, the lender will attempt to contact the home owner. Eventually they will foreclose. But that can take several months. Interest and late charges will continue to accrue.

May I ask what you ask the question?