Though I knew she was ill, this still breaks my heart. Like a lot of F&SF people, I was introduced to her books as a child with "A Wrinkle in Time" which was, and still remains, a favorite of mine, as are "A Swiftly Tilting Planet," "A Ring of Endless Light" and "A House Like a Lotus." And her non-YA work was also wonderful--a lot of it really heartbreaking. Madeleine had a way with flawed characters. She also wrote about New York. Several of her books took place on the Upper West Side, (which, as a Lower East Sider, I didn't hold against her) in or around the cathedral of St. John the Divine, one of the most beautiful churches in the city. I'm feeling very sad right now.