PLEASE HELP...

Solve this mystery! This morning I found this hole dug in the middle of 15 fairway. It is a square about 2' x 2' with sand packed in the bottom. Whomever dug it was kind enough to mark it with stakes and flagging. The tracts left in the fairway suggest a four wheeler was used to haul away the dirt. No real damage was done, we are fortunate that we just had sod delivered for the project on 7, so i can repair the hole today.
If you have any info or ideas please let me know! I have never seen something like this and I am very curious. Thanks, Jason.