Cersei Lannister. "The more people you love, the weaker you are. You'll do things for them that you know you shouldn't do. You'll act the fool to make them happy, to keep them safe. Love no one but your children."-George R.R. Martin, A Man Without Horror
Cersei kills everyone<<<It's possible, there are still pots of wildfire under King's Landing from The Mad King's rule and all of that just need a spark. She has said multiple times that if anything goes to harm her children, she would 'burn this city to the ground'