We are devastated to report that Sir Terry Pratchett has passed away. He was 66.

Terry Pratchett’s death was announced via Twitter, on his own account, in the most perfect, fitting way possible.

The BBC has confirmed that Pratchett has indeed passed away.

Anyone who has read Terry Pratchett’s Discworld books knows that Death is the most sympathetic, benevolent, and good-hearted person in his amazing universe, and so it is only appropriate that Pratchett should be sent off arm in arm with his most memorable creation.

In 2007, Pratchett was diagnosed with an early onset of Alzheimer’s disease. Despite his failing memory, Pratchett continued to write, both expanding the Discworld universe and veering off and telling new, original stories.

His latest completed work was The Long Earth trilogy, a collaboration with Stephen Baxter. The third novel, The Long Mars, was released last year.

Pratchett also worked with Neil Gaiman, and their fantastic book Good Omens was released as a radio play in December.

The phenomenal author’s contribution to the science fiction genre is immeasurable. His books were stock full of both humor and gravitas, exploring huge topics like love, death and the meaning of life while having you rolling on the floor with laughter. There was truly no mind like his.

Related: Remembering Terry Pratchett: Words of wisdom from Discworld

The Discworld series has followed this writer since early childhood; first it was the hilarious (and underrated) video game voiced by the Monty Python cast, and later the novels. Soul Music, one of the books centering on Death and his granddaughter, was a personal favorite.

While the world of the Disc introduced us to many colorful, long-lasting characters like Rincewind, Luggage, Granny Weatherwax, Susan and Sam Vines, it was Death who made the series so special. The way he was personified offered a great comfort to those experiencing bereavement, and we feel that it is very appropriate to keep this character in mind when trying to comprehend a loss like this one.

As Pratchett himself wrote in Equal Rites, “Death isn’t cruel. Merely terribly, terribly good at his job.”

Rest in peace, Terry Pratchett.