It's a great animation, I could understand part of (if any) the story behind it. Bart and Milhouse accidentally kill Maggie, and since Homer and Marge are nowhere around I can only assume since Krusty is in the hospital and it also shows a blank bed, Homer could have been drunk and wrecked into Krusty putting him in a coma, as for Marge I would assume after both Maggie's and Homer's deaths she commits suicide, and Liza finds her in the bathroom or something like that, all the while Bart feels overwhelming guilt since his actions inadvertently caused all of this so he jumps out of the tree. That is some dark and heavy things to convey through animation without any kind of voice acting but you did very well. I must say this is one of the best animations I have seen on this site in sometime, keep up the amazing work.