Why Did Rebekah Kill Elena?

Elena told Klaus about Rebekah's role in the attempt against his life in order to keep her daggered so she wouldn't come after her for daggering her. She began to dislike Elena for daggering her and not showing remorse for her actions. Rebekah tried to kill Elena to take revenge against her for daggering her.

Did Rebekah kill Elena's parents?

Stefan carried her to the shore and when he came back for Elena's parents, it was already too late and they had drowned. It was later revealed that Damon witnessed the recovery of Elena's parents bodies. This happened again caused by Rebekah, Elena died and became a vampire.

Why do the originals want to kill Elena?

Former Enemies/Allies; They dislike each other, Klaus is responsible for hurting and killing the ones Elena loves, Elena had no problem taking part in killing Klaus' brothers, Klaus killed Elena as a human (the first time), Elena tried to kill Klaus with her allies numerous times, Klaus only saw Elena as a vessel for ...