Philosophy has lost one of its greats, Fred Dretske. Among other things, he authored the classic Knowledge and the Flow of Information which is a key source for information-based semantic theories.
At a personal level, he was always kind and patient with me, a neuroscientist, peppering him with questions via email, or in-person after the philosophy colloquia I attended at Duke. I have about five pages of email correspondence with Dretske, correspondences that I will now treasure even more.
In this age of histrionics, he was a thoughtful, honest, and thorough thinker. He was often more thorough in discussing the weaknesses of his position than the people who thought they were providing original critiques of his work. He will be missed.