 Metallica rented an old Army barracks on the Presidio of San Francisco, California and converted it into a makeshift studio in January 2001. As plans were being made to enter the studio to write and record its first album in nearly five years, Metallica postponed the recording due to the departure of bassist Jason Newsted. Newsted left Metallica on January 17, 2001, stating his departure was due to "private and personal reasons and the physical damage I have done to myself over the years while playing the music that I love". Uncomfortable with immediately writing and recording with a new bassist, Metallica opted to include Bob Rock as bassist. The band stated they would find another bass player upon the album's completion.
