Sorry to hear about your mother and your brother.Your brother's children would receive his share of the proceeds.Your mother had designated her three children as beneficiaries of the life insurance policy.  The death of your brother results in his children receiving his share.Intestate succession means dying without a Will.  The rules of intestate succession determine inheritance which in this case would result in your brother's surviving children inheriting his share of the proceeds.  Your brother's children inherit his 1/3 and you and your other surviving sibling each inherit 1/3.