Dave Hirsch
The inyan of Shivah is to mourn and feel the pain, but that doesnt mean one may question Hashems ways. We say in Ashrei 3x every day Tzaddik Hashem Bchol Drachav Vechasid Bchol Maasav.
Its foolish to think we can understand “why.” Emunah means not questioning Hashems ways when things go bad, its easy to have Emunah when things are going great, its when things are difficult that Emunah kicks in and gives one the strength to go on knowing that Hashem will sort things out.