In traditional Astrology ,longevity of an individual is calculated from his eight house,eighth lord and aspect of others planets on eight house.Generally malefic planets locates in eighth house inceses the longevity rather than the presence of beneficial planets in eighth house.Similarly Dasha and Sub Dasha of eighth lord or planets in eighth house indicates the possibility of death. But such rules are not always practically implemented in true sense.Death is the consequence of life guided completely by the almighty or super natural power, whatever we define. In few cases the prediction of an Astrologer may accurate.For an Astrologer, it is better to draw a tentative conclusion or draw an apparent prediction of possibility of untoward consequence in life to aware an individual regarding his longevity.