See heart attack
is one of the common and important cause of natural sudden death, please accept my condolence.He may be suffering with hypertension
,undetected and suffered a sudden death,nose bleed may also come from intrcerebral haemorrage along with heart attack or cardiac arrest
There are many causes of Epistaxis
(Nose Bleed) may be High B.P.(most likely), any alcohol intake,Aspirin
,or NSAID or trauma.
If it natural death ,we should pray to god to rest his soul in peace, and unnatural death is there then it is more of alegal issue.
If sudden death occurs in family other members should take care of health and take up preventive medical checkup.
Good luck to you