Your Trash Bin
Anytime you delete an asset, it goes into the WCMS "Trash". You can access the Trash right above your folder structure:
Items in the Trash are stored there for 30 days. So, if you delete something by mistake, don't worry! You can "Restore" the item.
Remember, deleting an asset automatically un-publishes it. After you restore the item, re-publish the folder. This publishes the page AND updates your left navigation.