My sibling's stole my deceased mom's banking account. What do I do?

The day after my mother died in this disgusting act of disrespect. Later I was served paper's for what I had No idea for mintgs what!?.Months went by,I never looked at the Papers I was served, Then one day I opened them, I saw that my Mother took out a second Mortgage to fix her home ,she had received a ,amount of 80,000 dollars .The day My beloved Mother Died My Sister the oldest had the same name as My Mother and went to the Bank withdrew all the Money I'm assuming because she ,her family and My youngest Sister rented a truck loaded all the pilage items from the home Without a Will proof of the Executor of the will