Re: Half my tooth fell out after root canal
Chances are there wasn't enough "good" tooth left. Once a tooth has had a root canal they can become more brittle, too. I don't think it had anything to do with the lack of a permanent crown. It's actually lucky that it didn't break after your perm crown was placed. Others with first hand experience may be able to shed more light on it, but unfortunately, it probably just happened.
Hope this helps.
Best to you,