Please help my succulent!i

I walked by this guy today and noticed almost all his leaves were suddenly detached. I'm not sure what happened. I gave him a little water yesterday and will be changing his soil today to a more gritty soil but he was fine yesterday and today all these parts are off. :( can his leaves be planted to grow another one also? He is in a SE facing window and I only water him a little once every two or three weeks.