The Monterey cypress tree was located at Ellen Browning Scripps Park in La Jolla, California, the seaside resort where author Theodor Seuss Geisel lived from 1948 to his death in 1991.
The tree would be between 80 and 100 years old, said Tim Graham, spokesman for the Parks and Recreation Department of San Diego.
He said that there was "no definitive cause on the reason for his downfall".
The city plans to retrieve the big trunk in hopes of reusing it, Graham said.
Most of the tree was removed on Friday and the remaining large trunk should be removed later this week. The city will seek to install a replacement in the area, said Graham.
"The Lorax" follows the titular character who tries to defend the precious fictional Truffula trees and the creatures that depend on them for their survival in the face of corporate greed.
The book was turned into an animated film in 2012.