Harper Lee: 'To Kill a Mockingbird' Author Dies at 89

Beloved author Harper Lee, who wrote the American classic "To Kill a Mockingbird" has died in her Alabama hometown.

A source close to the situation tells TMZ Lee was found at home and appears to have died from natural causes ... at this point an autopsy has not been scheduled.

Lee's Pulitzer Prize winning novel was published in 1960 and became a classic movie as well, 2 years later ... starring Gregory Peck.

'Mockingbird' was Lee's first and only novel -- up until 2014 when a manuscript was found of her first draft of the book. That was published in 2015 under the title "Go Set a Watchman."

Lee, who suffered a stroke in 2007, lived most of her life in her native Monroeville, AL.

Time has called 'Mockingbird' the greatest novel of all time. The movie version won 3 Oscars. Just last week it was announced Aaron Sorkin will adapt it for a Broadway play.

Harper Lee was 89.