Did you know most hosting companies do not take backups of your website? What will you do if your site is hacked?
I've actually had this happen before with a personal site.
My host was nice enough to actually give me a chance to get my data off the site, before I wiped it
The very first thing they did was cut off access from the server out, so it wouldn't affect anyone else. Pretty good idea.
If you're lucky, you might have a host like mine, and actually be able to get your data out. If not... you're out of luck
I did have a backup plan, and I did put it into effect.
Lesson 0: Backups are like shoelaces. Left undone, you will trip and break your face, and its too important to leave to other people. I managed to recover the site from my last known good backups, so all was good.
Lesson 0.0: Build your site with security in mind to start with
Lesson 1: If you can, keep a copy of the site contents for threat analysis. In my case, someone brute forced my root password
Lesson 2: Learn from lesson 1. When you rebuild your site, make sure you don't make the same mistakes again. My new server has key based auth, I considered building it without a root account.
I'd also add, shared hosting can be a pain, and I tend to run a VPS or a dedicated server these days.