5:55 AM PT -- The New York Post is reporting the incident that triggered the firing occurred at the Rio Olympics, when Lauer allegedly assaulted a female NBC staffer.
5:46 AM PT -- Sources connected to NBC tell TMZ the network has been investigating Lauer for weeks and multiple media outlets -- including the New York Times -- were working a story about the anchor and sexual harassment. As one source put it, "Lack tried to get ahead of the story before it broke."
Matt Lauer is no longer the face of NBC's "Today" -- he's been fired for "inappropriate sexual behavior.