The Last Dragon Star Dies

Leo played Bruce Leroy's little brother Richie Green in the 1985 cult classic film.

Details surrounding O'Brien's death are unclear ... but law enforcement sources tell us the actor passed away Wednesday morning, and an autopsy was scheduled for Thursday.

Leo's "Dragon" co-star Taimak (sho 'nuff) says family members believe O'Brien had been in failing health recently.

As TMZ first reported ... O'Brien survived two gunshot wounds just over a year ago in Harlem. Police arrested a suspect who was charged with attempted murder.