Very bad news about David Hartwell, one of most important editors of science fiction and fantasy: According to Kathryn Cramer, David has had a massive bleed in his brain and is not expected to recover. Patrick Nielsen Hayden, who has known and worked with David for decades, has further thoughts and information.
I’ve also known David for a number of years; his knowledge of and passion for science fiction and fantasy literature is beyond contestation. My thoughts are now to Kathryn, their children and family, and all who know David, personally and professionally. This is a significant loss for the field.
Edit, 8pm: Kathryn Cramer reports via a Facebook comment to Neil Gaiman that David has indeed passed away. May his memory be a blessing to all who knew him.