<P> Tommy followed in his father's footsteps and became a firefighter in 1986 . Tommy was first assigned as a "Probie" or Probationary Firefighter to a firehouse in the Meatpacking District of Manhattan . Throughout his career, Tommy has transferred several times to firehouses in both Brooklyn and Uptown Manhattan . Tommy is currently the Senior Firefighter, or "Senior Man" of New York City Fire Department Ladder Company 62 (a.k.a. "62 Truck"), quartered with Engine Company 99 and the Chief of the 15th (later 30th) Battalion in northern Harlem, Manhattan . During one season of the show, Tommy was temporarily transferred to Engine Co. 336 / Ladder Co. 73, a firehouse on Staten Island . Tommy's fire company and firehouse lost four men during the attacks of 9 / 11, one of whom was Tommy's cousin and best friend, Jimmy Keefe . Jimmy had been the Senior Man of 62 Truck prior to his death . Tommy also personally knew fifty - six other firefighters who were killed on 9 / 11 . Tommy is also a motivational speaker / consultant for the New York City Fire Academy, as seen in the pilot and final episodes . Tommy is a working class, blue collar personality with skills in carpentry, mechanics and plumbing as well as his firefighting career . Tommy likes to drive pickup trucks as his personal vehicle including a mid 90s Ford F - 150, a new Cadillac Escalade (briefly, after being given it as a gift by Jimmy's widow Sheila), and a Dodge Ram 1500 . Tommy has also shown skill in hand - to - hand combat and firearms usage . </P> <P> Tommy is married to his high school sweetheart Janet Gavin, who became pregnant with their oldest daughter, Colleen, when she was only seventeen . The two are "separated" numerous times, but the announcement is occasionally followed by Tommy stating that they never filed for divorce, making the couple technically still married throughout the entire series . Their relationship is mostly estranged, however at some points they appear to be friendly . They've had five children together, two girls (Colleen and Katy) and three boys (Wyatt, Shea, and the late Connor). Connor was killed in a hit - and - run accident, putting further strain on Tommy and Janet's relationship, and causing Tommy to become a fully relapsed alcoholic . Wyatt, however, is strongly believed by both Tommy and Janet to be the product of Janet's affair with Tommy's brother, NYPD Detective Johnny Gavin, who had been killed in the line of duty, although a paternity test was never done . Tommy is also throughout the series in an off - and - on affair with his dead cousin's widow, Sheila Keefe . The two are seen sleeping together numerous times on the basis of sharing mutual grief over Jimmy Keefe's death, fueled by Tommy's troubled relationship with Janet . (Tommy was punished by the subordinate firefighters in his house for it in the season 1 finale, as "widow banging" was a forbidden act in the FDNY, however despite the continuing of it throughout the series, no further discipline ever happened .) </P> <P> Tommy is a tortured character . He is a relapsed alcoholic, as well as a chain - smoker and a prescription - drug addict as due to his role as a first responder to the World Trade Center attacks on 9 / 11 . Throughout the series, a recurring theme is that Tommy is highly mentally and emotionally disturbed as a result of what he witnessed on 9 / 11 . Because of the painful loss he endured, Tommy suffers from survivor's guilt and severe PTSD . Tommy is often visited by "ghosts," deceased people from his past - most frequently his cousin Jimmy and other firefighters who died on 9 / 11 - as well as fire victims he could not save . It is left ambiguous whether these are real ghosts or figments of Tommy's imagination . </P> <P> For the first, fifth, sixth, and seventh seasons, Tommy lives in Queens . During the second, third, and fourth season, Tommy lived in various apartments in Manhattan . </P>

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