Juliet's Death
I believe that her father Lord Capulet played a large role leading to Juliet's eventual suicide. If he hadn't given Juliet away to Paris then maybe he could've approved of Romeo eventually with enough persistent effort by Romeo and Juliet, but instead he did give Juliet away resulting in her heart being crushed and a bond broken between the two that could never be rebuilt. In a way to avoid her fathers arranged marriage Juliet devises a plan which eventually back fries,, with her ending her own life beside Romeo in their family crypt.