The Red Admirals Meet Their Watery Grave

This may seem unrelated and random, but I thought I would share this unusual phenomenon that happened to me over the weekend.  I plan on turning this into some sort of photographic project.

I just got back from an amazing trip to the Saugatuck, MI area.  I was able to do some real communing with nature there, some of it unexpected.  My boyfriend and I spent a day relaxing at the Saugatuck Dunes State Park beach, which is a mile hike in from any road.  While walking where the surf meets the sand, I noticed something strange.  I kept seeing butterfly wings stuck in the sand.

Upon closer inspection I found dozens of butterflies, or just butterfly wings, scattered along the beach.  It wasn't long until I found a butterfly being battered by the incoming waves and ran to find a stick that it could grasp onto.  I fished it out and placed it on dry sand.  I didn't really know what was causing this mass grave, though I did find that some of the butterflies I came across were still alive!  Their wings would be wet or laden with sand so they were immobilized; the incessant waves eventually drowning them because they couldn't fly out of their reach.

I spent probably the next hour or so walking up and down the beach looking for and carefully digging out these Red Admiral butterflies, as I later found out they were called.

In the end I think I might've dug out about ten Red Admirals that were eventually able to fly off into the grassy dunes.  It was amazing to watch them pump their wings to dry them off so the rest of the wet sand could fall off of them.  I was lucky to be able to get so close to them and take loads of pictures, though frankly many weren't in any position to protest.  These are just a few (unedited) pictures that I snapped.

I'm sure there is some easy explanation for this circumstance, like that the butterflies would just go down to the lake to drink the water, only to get caught by a wave and brought down to a waterlogged death.  But so many of just one species at one time?