No one wants to think about your house catching on fire, or being damaged or destroyed in a natural disaster. But disasters do happen, and you can't afford to have all your eggs in one basket.
I've talked previously about backing up your work, but this is another level of security that you may want to consider. If you keep your back-up files in your house, a fire could still mean you lose all your work. A fire-proof safe is a good idea, but if the safe gets hot enough the contents inside may well melt or burn. And if you're anything like me, you don't back up to your safe-kept thumb drive nearly often enough, even if you back up to your laptop or other device nightly.
There are a number of options available. You can keep copies of your work on disc or drive at a friend or family member's house, or even in a safe deposit box, but this will only be as up-to-date as you make it. Make sure your plan is reasonable. It does no good to have a plan you continually neglect to implement. However, old files are still better than no files.
You can also email files to yourself. This can be particularly effective if you are emailing from one email address to a different one—double the coverage for the same amount of work. There is a small risk of your email account getting hacked or the email provider losing your files. Alternatively, if you have a trusted writing buddy or buddies you often send files to for critiquing, see if they will keep a folder of your stuff on their computer or in their email.
If you have trusted computer savvy friends, you might consider setting up file servers at each other's houses. This allows you to back up your files to your friend's computer, and vice versa, without necessarily having to go through email.
There are also back-up software packages and online services you can use. Research these heavily. There is always a risk in giving your files to someone else. Make sure they encrypt the files. Expect to pay for this service.
Test your back-ups to make sure they work, and check your logs if you're using software or an automatic back-up to make sure things are being backed up properly. You don't want to go through all that trouble, only to find out that there was a setting that wasn't right and you've lost everything anyway.