Kevin's death was so shocking and sudden. He had only been on the show for around three seasons, and had already been adopted by the Winchesters. Crowley had warned him that all the Winchesters do is hurt the people they love. Kevin is trapped in the veil and they have to face his ghost, and find his mother. Eventually, he does end up going to Heav
I think that Charlie's death was one of the most horrifying in the show because she was so innocent and kind. All she wanted to do was save her friend (more like a brother) and she was stabbed to death and left in a bathtub. :(