The Glee cast met last week for a private ceremony commemorating the life of late castmember Cory Monteith, but they've also been expressing their feelings publicly. Recently, Cory's longtime girlfriend and costar Lea Michele finally broke her silence on Twitter and Darren Criss spoke outduring and appearance on Conan. While his death has inspired an outpouring of emotional reactions from celebrities who knew and loved him, the news has undoubtedly hit his costars the hardest. Mike O'Malley (aka Burt Hummel) also recently spoke at the Summer TCA about working with Monteith on the Glee set. Click through to see the heartfelt messages from Monteith's fellow Glee stars and famous friends.