Another WHY question

My teen friend Kara went in to the dentist to have her wisdom teeth removed Friday (9/2). She never woke up from the anestesia. How can this happen? Why did this happen? She was air lifted to the hospital shortly after she didn't awake. They have been running all kinds of tests but still are not sure what's going on. They have theories but nothing conclusive.
I still wake up thinking this is a bad dream. How can a girl (she's 15) go to the dentist and never wake up. Why would God allow this to happen. She is such a great girl. She has so much going for her. It's been very sad to see her in the hospital not responsive to anything. All the wires and tubes hooked up to her. Occasionally she wakes up for a few seconds but then... back to sleep unresponsive to anything. It's been four days now. WHY WHY WHY?
God, please allow her a full recovery NOW, TODAY!.