Sorry to hear that. Backups? Copies of data sent to supervisor? Emailed? Attachments?
Worst case - old printed copies and pay to have them re-typed?
I strongly urge you to have the disk mounted in a different enclosure and mount it read-only on a different system entirely. It may be possible to find the file(s). I would suggest a BSD or Linux system where a disk is not forced in to write-mode on boot. Windows is a terrible system to use for data recovery unless you have a drive adaptor which can force read-only.
Hard drives fail for various reasons. The platters themselves go bad (actually rare), the read/write heads fail ( quite common with large capacity disks) or the electronics board fails. The board can sometimes be swapped with another from the same make and model, replacing heads is nontrivial and if the platters have gone there is very little chance of recovery.
I used to sysadmin and also do disk forensics and the worst case was always a student with no backups. Data recovery companies charge a lot but it is hard work with modern drives.
BFTA Secretary 2012-2014
CSFTA Secretary 2014-2016