We lost Terry Pratchett today.

The last Tweet may make you laugh -- that's why it's at the end -- because you may have been weeping ever since you found out.  Like me.

How to be a writer, by Terry Pratchett: pic.twitter.com/vqc3wzwiRo
— The Beer Nut (@thebeernut) March 12, 2015

Jim Hines made a storify of Terry's final Tweets here.  If you read any of Terry's books, these three will make you weep.

Jo Walton's anecdote about Terry Pratchett refusing a Hugo nomination is, well, both very Terry and very teary. http://t.co/6geWR1rGrn
— Ferrett Steinmetz (@ferretthimself) March 12, 2015

Rest in peace, Terry Pratchett. http://t.co/9WeByQX2SL pic.twitter.com/NNsaGSukIl
— Cory Doctorow (@doctorow) March 12, 2015

2012 news about Discworld being handed off to his daughter.

DON’T THINK OF IT AS DYING, said Death. JUST THINK OF IT AS LEAVING EARLY TO AVOID THE RUSH.” http://t.co/D16vHe7Dl3 pic.twitter.com/JgZ0cwcP7a
— Cory Doctorow (@doctorow) March 12, 2015

ETA:  BBC tribute article.
ETA 2:  The MarySue's update includes Tweets from Neil Gaiman and [Terry's daughter] Rhianna Pratchett and other links; and this Tweet.

Tor.com has an obit -- if you want to help out, please read it, and check out the designated charity set up in Terry's memory.

Neil Gaiman understandably couldn't write about losing Terry today.  This is what Neil wrote for the Guardian about what fueled Terry last year.

Here, have another tissue... 8(