Complex sentence: On 25 October 1980, at the age of fifty-nine, Sahir died a sudden cardiac death (he had been a smoker and drinker) in the presence of his friend, Rishi Kapoor.
Split into simpler sentences: On 25 October 1980, at the age of fifty-nine, Sahir died a sudden cardiac death (he had been a smoker and drinker). He died in the presence of his friend, Rishi Kapoor.