You are not going to lose your pictures if there's a hard drive crash in the cloud. There are all sorts of redundant storage implemented in iCloud. However, it's mo guarantee that you are not going to lose some or all of your pictures. One example that comes to mind is if your account is hacked. Another one is if you make a mistake and accidentally delete a certain photo. I would suggest making a copy of your library and keeping it off site.
4/10/15 at 4:09pm