This is so sad. The Sun Times just reported on Twitter:

Just two days ago, Ebert reported that his cancer had returned, but he was still full of plans for the future. He leaves behind a tremendous body of work that will influence film critics for many years to come. The Esquire profile of him from 2010, which hopefully will be pulled out from behind a paywall soon, Neil Steinberg's obituary in the Sun Times gets it right.