Harper Lee, the author behind the literary classic To Kill A Mockingbird and the more recent novel Go Set A Watchman has passed away at age 89.

The Pulitzer Prize winning author's passing was confirmed by the city clerk in Monroeville, AL, where Lee lived, though it is unclear when exactly or how she passed.

Lee's 1960 novel, about racial tensions in the South as viewed by the daughter of a white lawyer defending a black man on trial for the rape of a white woman, was a critical and instant success, earning her the Pulitzer one year after it was released. She became a reluctant celebrity in the literature world afterwards, though her lack of publishing a second novel until 2015 frustrated many of her fans over the years.

Regardless of those frustrations, however, many have taken to social media to express their sorrow over Lee's death, with many thanking her for the message she sent with her writing and crediting her for their love of literature, while celebrities and other fellow authors also expressed their sorrow over her death: