Celebrities reacted to the death of Robin Williams on Monday afternoon as news of the tragic loss quickly spread.

Update 2 (Tuesday, 7:30 a.m. pacific): Aladdin composer Alan Menke and Williams’ The Crazy Ones co-star Sarah Michelle Gellar have shared thoughts:

Alan Menke (via Billboard): “If I had only watched Robin Williams on the TV screen, in the movies or on stage, I would consider myself blessed for having simply experienced his brilliance, his joy, his humor and his heart. The fact that I had the honor of sharing the creative process with him is an honor and a privilege that I will cherish for the rest of my life.””

Sarah Michelle Gellar (via People): “My life is a better place because I knew Robin Williams,” Gellar said. “To my children he was Uncle Robin, to everyone he worked with, he was the best boss anyone had ever known, and to me he was not just an inspiration but he was the Father I had always dreamed of having. There are not enough adjectives to describe the light he was, to anyone that ever had the pleasure to meet him. I will miss him everyday, but I know the memory of him will live on. And to his family, I thank them for letting us know him and seeing the joy they brought him. Us crazy ones love you. God, grant me the serenity to accept the things I cannot change, the courage to change the things I can, and the wisdom to know the difference.”

Update 1 (8:15 p.m. pacific): TBS has released a clip from tonight’s episode of Conan during which O’Brien, Andy Richter, and guest Will Arnett discuss Williams:

Here are several tweets we gathered together from all types of Hollywood names. Some of them worked closely with Williams professionally, while others simply admired his work:

In addition to these, Williams’ wife issued a statement shortly after police first reported his passing: “This morning, I lost my husband and my best friend, while the world lost one of its most beloved artists and beautiful human begins. I am utterly heartbroken.”

Williams was 63.