As has been announced by Lance and Mihai, Avner Magen just died in a climbing accident in Alaska (there's a memorial blog set up in his name).
I didn't know Avner personally, but I've "met" him through a few of his papers. Among the many things he did were some very nice early results in the theory of metric embeddings. With Nati Linial and Michael Saks, he showed how to embed trees into Euclidean metrics with low (O(log log n)) distortion. And in a later result, he showed how to do JL-style embeddings that preserved not only distances, but also higher order volumes (improvements here)
This last result has been of particular interest in some of the work I've been doing of late - we've been interested in arc-length preserving embeddings that relate to volume preservation, and I've also had a student looking at some near neighbor problems for higher dimensional objects.
It's very sad to read such recent works and know that the person who wrote them is no more. My condolences to his family and friends.