Well, you were injured. Badly. And Meredith used Damon's blood to cure you, because otherwise you would have died. And his blood was still in your system when Rebekah ran you and Matt off Wickery Bridge on your way back into town. I was close by. I tried to save you, you told me to save Matt instead.
You drowned. But Alaric's life was linked to yours, so when you died, he died as well.