http://tswatch.tumblr.com is tumblr suicide watch. They are not affiliated with Tumblr, nor do they work for Tumblr, nor are they healthcare professionals. They are a group of volunteers in the Tumblr community who try talking people out of suicide.
If you know of anyone on tumblr considering suicide, attempting, or having suicide intentions of any sort, MESSAGE THIS BLOG AND THEY WILL HELP.