[2] At age 17, Hansen began working part-time at the Presidio branch of the San Francisco Public Library.
[4] In 1989, Hansen co-authored the book Denial of Disaster, claiming that the number of casualties from the earthquake was dramatically and deliberately understated.
[4] Hansen retired from the San Francisco Main Library in 1992, but continued her work on identifying earthquake victims.
[3] In 2005, the San Francisco Board of Supervisors unanimously passed a resolution, co-authored by Hansen, that set aside the official 1907 death count.
[2][6] In 1997, Hansen received the Ron Ross Founder's Award from the San Francisco History Association.