Check to see who deleted a folder

You can try LepideAuditor for File Server to track file and folder deletions along with you can set up an alert for delete action and every time someone deletes you'll get alerted via e-mail in real time.

Check the below article to get in detailed description of the procedure for tracking file deletions on Windows File Servers: https://www.lepide.com/how-to/track-file-deletions-and-permission-changes-on-file-servers.html

I agree with masnrock, you first need to turn on auditing from either local policies or domain policies and apply it to the machine you want to audit.

Once the policy is set you need to configure auditing on everything you want to audit, and that will start adding events to the event log.

GPEDIT:

Computer Configuration --> Windows Settings --> Security Settings --> Local Policies --> Audit Policy --> Audit object Access

You can turn on success and then it would create a failure, so you dont want to monitor those events.

Here are more reference for doing this

http://www.monitorware.com/common/en/articles/audit_file_deletion.php

http://www.poweradmin.com/file-sight/

https://www.netfort.com/languardian/solutions/file-activity-monitoring/

https://www.netwrix.com/how_to_detect_who_deleted_file.html

Hope it help

so I do have it turned on. is this incorrect?

Go through the article, there are other GP  you need enable, after enabling those you can install DFSR  and create a report to send a mail notification.

https://blogs.technet.microsoft.com/mspfe/2013/08/26/auditing-file-access-on-file-servers/