I like how ZetaZaku mentioned Mufasa's death in The Lion King, as that was probably my first real 'experience with death,' since that was and still is my favorite Disney movie. I watched it obsessively when I was 4-5 so I'm guessing that's when I started to understand it; I'm glad I wasn't really sheltered from it. Let's not forget Bambi's mom and The Fox and The Hound u_u
Death wasn't so censored in the 90s, either, I remember Chuckie's mom in The Rugrats had a big part on his character and development. Hey Arnold! had his parents who were either dead or missing, but either way they were out of the picture and it was implied that Arnold was pretty much orphaned.