Finding Jimmy Hoffa

I love this pic from Down With Detroit   (they have awesome stuff).  Anyway, someone posted this pic on our Facebook page and said we should solve this case.  My reply was that we don't have a backhoe in our toolkit.  What do you think it will take to solve this case and do you think it ever will be?
Here is Down With Detroit's website where you can see this design and many others:
 www.downwithdetroit.com

Photo from Down With Detroit Facebook page:  https://www.facebook.com/photo.php?fbid=10151635312371702&set=a.68651281701.71239.6048971701&type=1&theater