Simplify the following text for a Grade 8 native English-speaking person.
Original: Gambino was known for being low-key and secretive and unlike many modern mobsters , Gambino served no time in prison , but lived to the age of 74 , when he died of a heart attack in bed .
Simplified: Gambino was known for being low-key and secretive . Gambino served 22 months in prison ( 1938 â `` 39 ) , and lived to the age of 74 , when he died of a heart attack in bed , `` In a state of grace '' , according to a priest who had given him the Last Rites of the Catholic Church .