It’s funny how we celebrate birthdays so highly and deathdays (when you die) so not highly. I mean, yes, you can view death as something really tragic, but isn’t the truth that death is just as celebrative as life is. Thanks to death, we have life. One is not to be feared and one loved, they are just as essential for this world that we live in.
But yes, it is obviously natural to feel sad when someone you liked very much passes away. The important thing is to not be angry at or fear death. Because if there was never any death, there would never have been any life. I mean, where did you come from, if not nothingness (death), and where are you going back to, if not the same place? In the end death is not something tragic, it is essential.