Popular Death Riddle

According to an old story , once there was a father and his three loving sons. One day dad met an serious accident , death approached to take the father. Oldest son beg to the death to allow his father to live for some more years. Death was kind and agreed.After 2 years death return to take the father with him , now the second son beg for some more time. Death agreed.
After a year death returned again to take the father.Now the youngest son request to allow his father to live till the candle wick of the candle on his hand burned out.Death agreed.

Now as the youngest son thought , the death never returned back.