Lost baby at 21 weeks

Well I got confirmation today that my baby passed away. I had not felt any movement for about a week, right after my anatomy scan last Tuesday where everything looked great. A few days went by where I didn't felt anything, I emailed my doctor and they said it can be normal, but by last night and still not feeling anything I decided to get checked out today. And they confirmed there was no heartbeat. Going in for induction tomorrow. Just wish I could know what happened. 😢