Damien Darhk blackmailed your dad into working for him by threatening her. Your dad testified against him and worked with us to try and bring him down. He was arrested and was in prison, powerless. Then Dig's brother betrayed us and helped Merlyn break him out and get his power back. Laurel and the team went to try and stop them. Damien froze Oliver and stabbed Laurel to fulfill his promise to your dad.
She made it through surgery and we thought she was going to be okay but then she had a seizure. Sara, I'm so sorry but Laurel is gone.