It was my first or second year of teaching when I lost my first student. He was new to school that week, quiet, didn't turn any work in, and I didn't pester him about it because I figured he was still getting his bearings. He didn't come back to school after the weekend; I was thankful I didn't know him well. I know that sounds callous, but that's the way it was.
In the intervening years I've lost a couple of former students, but (fortunately for me) they weren't students with whom I'd developed strong relationships. They were people whose names I recognized, yes, but not one of those few students with whom you sometimes build that extra strong relationship with.
Tonight I'm going to see several members of last year's graduating class. These aren't the conditions under which I'd hoped I'd see them again.
But when you deal with hundreds of new people year after year after year, eventually it happens. And it's going to be difficult, especially since she was so young.
Update: That was difficult.