Mortgage Still being paid after owner passed away

[Joy Williams]

A friend of the family lives in a home where the home owner passed away 5 years ago. The HO was the only person on the mortgage. Her husband continued to pay the mortgage through automatic deductions from their shared account. He recently passed and the son currently lives in the home but the mortgage is delinquent as of December 2015.  What happens to the house? I assume it will go into foreclosure since no payment since December but could the son try to get the bank to allow him to buy it?  What if it sells for more than is owed on the mortgage - assuming he can get current on the payments - who is entitled to the overage?  Thanks in advance for any insight in to this BP!