When I first saw the announcement I didn't believe it at first. 33 is way too damn young. He will be missed very much by his family, friends, and fans. RWBY, if it continues and I think it will, simply not be the same without him. This man will always be one of my absolute favorite animators, and his work will always be incredible, I'm just sorry we won't get to see anymore of it.
I want to say something poignant right here but I honestly can't think of anything except that Monty wouldn't want us to grieve so much that we forget what he accomplished.
"I believe that the human spirit is indomitable. If you endeavor to achieve, it will happen given enough resolve. It may not be immediate, and often your greater dreams is something you will not achieve within your own lifetime. The effort you put forth to anything transcends yourself, for there is no futility even in death." -Monty Oum 1981-2015
Rest in Peace Monty.