Voting Question: My father died, were my sisters and I entitled to anything?

Probate Law: My father passed away June 16, 2004. I don’t know if he had a will or testament. He and my mother divorced 2 years prior to his death. He was survived by his estranged father as well as his sister. My sisters and I received SS benefits until we turned 18 years old or graduated. My father had a life insurance policy, which we couldn’t have been named beneficiaries on because we were never contacted about it. I was young when he passed (17) years old and have since wondered where or to whom the rest of his funds were distributed to. 401K, severance pay, etc…My mother never pursued anything for us, except SS which she took every dime of. We never received anything besides the SS, were we not entitled to any of his estate? His property, his home, his cars? I cannot imagine him ever leaving everything to his father since they had never had a good relationship. I have contacted Anthem and they refused to give me any information as to who made the claim his monies. I also contacted his place of employment for verifiable records to see who had name beneficiaries on anything he left, they say they can’t release his file to me either. I can’t fathom that my father left us with nothing. This is mind boggling, he loved us alot and he had to have to known that if he named my grandfather as beneficiary, we would have never received anything. He died such a long time ago, is there anything I can do? Any way I can find any information out? Were we entitled to anything at all? We live in Indiana…Could there be a limit on how long you have file a claim on his things?