To Kill a Mockingbird and Go Set a Watchman author Harper Lee has died. The 89-year-old passed away on Friday at the assisted living facility in Alabama where she lived.

The great Harper Lee has died at the age of 89. https://t.co/MxfqEdkhZj

— John Green (@johngreen) February 19, 2016

According to a report from the Hollywood Reporter, Lee’s publisher said she “died peacefully.”

Harper Lee’s prizewinning novel To Kill a Mockingbird was published in 1960. Set in the 1930’s, character Atticus Finch–a lawyer–defended an African-American man named Tom Robinson, who was accused of rape.

Lee wrote Go Set a Watchman prior to writing To Kill a Mockingbird, but it was only published last year. The New York Times shocked readers when it reviewed the book, writing that Atticus Finch was a racist.

Harper Lee didn’t live to see To Kill a Mockingbird open on Broadway. Scheduled to be revived in time for the 2017-18 season, its stage adaptation was written by Social Network and West Wing writer Aaron Sorkin.

Celebrities react to Harper Lee's death: https://t.co/nKH3CSJrxl pic.twitter.com/kL8Lpknfzz

— Entertainment Weekly (@EW) February 19, 2016

Sorkin issued a statement Friday after learning Lee had passed away.

“Like millions of others, I was saddened to learn this morning of the passing of Harper Lee, one of America’s most beloved authors. I’m honored to have the opportunity to adapt her seminal novel for the stage,” he said.

Were you a fan of To Kill a Mockingbird and/or Go Set a Watchman? If so, you are no doubt mourning the passing of Harper Lee.