The guys on the left (one with shovel) were responsible. They said they were doing it for fun, and hawked rides to any passers-by--and when we left at 7, they were out there building it up further. "Now our professor wants it to be an experiment," they said, still grinning.
I knew those guys. I mean, I don't know those guys, but there are a bunch of people reading my friends list right now who did stuff much like this, back in the day... Oh, my school. *heart*
And the library folks are like, "Well, they're not destroying any property, so..." And then half our office went out and sledded. *hearts my library, too*