The man who died was identified as 58-year-old Martin Gonzalez of Oakland, who had worked for the company for 17 years, according to ABC 7.
The second employee, a woman, was taken to a hospital with minor injuries, a spokesperson for the Oakland Fire Department told The Times.
Fire crews responded to the warehouse in the 600 block of 85th Avenue shortly after 3 a.m. Friday, according to the Fire Department. Gonzalez was among the few employees in the building at the time.
As a distribution leader, he arrived about an hour before other employees to prepare for the day. Had the accident occurred hours later, more people probably would have been seriously hurt, the Fire Department spokesperson said.
The roof collapse was contained to an area of about 30 by 30 feet. The building has been red-tagged.
Officials have not directly linked the collapse to the storms that have caused widespread damage and flooding in Northern California but were investigating that as a potential cause.
Peet’s said in a statement: “We are all devastated by this tragedy” and described Gonzalez as “a beloved part of the Peet’s family.”
Times staff writer Jessica Garrison contributed to this report.