I'm lucky to still have my parents alive. But the most tragic of all death I have seen was when I lost my aunt and my grandmother to death on the same day, six years ago. Whenever it's my grandma's birthday, I usually place her portrait on the chair she used to sit and tell me moonlight tales.
That must have been tough to lose both on the same day, I can only imagine what that might be like. Hopefully you managed to work your way through it and you remember both of them with fondness and love.