Q. Can I un-delete an assignment that was deleted by accident?

Yes.

Go to the home page of the course and type "/undelete" on the end of the course URL. This address will take you to a page that will list all the items you have deleted on that course site.  Click the “restore” button next to the item you want to bring back and then click “ok” to confirm.  Please Note: if this was a published item, students will be able to see it once you restore it.