Is there anyway to retrieve someone who was accidentally deleted?

Don't worry, it is possible to restore deleted student data. You no longer have access to student data after it's been removed, but we can get it back for you.

I won't be able to do it tonight, but we'll work on it tomorrow. We'll restore all deleted students for your event. Any that you intended to delete you'll need to delete again.  

We'll have the student data restored by end of day tomorrow.

We're in the process of making some changes that will make it simpler to restore participant data, so we'll be able to respond faster the next time someone needs this done.

I have restored all the deleted students from your account. You'll need to go back in and delete the duplicates again, but you haven't lost anything.