Assistant Deputy Chief Thomas Doudiet, a third-generation native San Franciscan, entered the San Francisco Fire Department in 1979. He was promoted to the rank of Lieutenant in 1988 and Captain in 2009. By 1991 ADC Doudiet had worked at every Fire Station in the City. Prior to his appointment to the position of ADC of the Division of Support Services in July 2010, ADC Doudiet was assigned as one of the Station Officers overseeing the daily operations of San Francisco’s Fireboats.

ADC Doudiet has made additional contributions to the Department by expanding the Portable Water Supply System (PWSS). The PWSS, invented by Assistant Chief Frank Blackburn in the 1980's, is the water supply system that was deployed during the 1989 Loma Prieta Earthquake to extinguish the major blaze in the Marina District. ADC Doudiet realized the need to expand this critical fire suppression tool and has led the development of a prototype system of trailers, or PWSS Units - consisting of portable hydrants and large diameter hoses, on which to deploy the PWSS.

Prior to his career with the Fire Department, ADC Doudiet, a graduate of George Washington High School, attended San Francisco City College and the University of San Francisco, where he majored in History and obtained his State credential for teaching high school. He taught Social Studies and Physical Education at his alma mater from 1972 to 1978.