You do backups of your TNG data and regularly, right? Of course, we all have those great intentions. We plan to back up weekly, or monthly or quarterly, or whatever inspires us. Nope; instead we toil away every night, plowing in more and more genealogy information. That is way more fun and satisfying. Or perhaps we are not doing backups because we don’t know just how easy it is.
UPDATE as of September 2018: Your TNG Team has added an automated backup routine for your TNG site. Each Monday, early in the morning and depending on your local time zone, your TNG website is automatically backed up, using the built-in backup utility of TNG. You can still elect to do your own backups, especially if major changes are done. However, you also have the comfort of knowing your backups are being done, regularly, behind the scenes. And you can restore the backup at any time.
Find more information on how to do TNG backups and restores, at the TNG Wiki tutorial site.