sentences:  John T. O'Hagan
  
  John T. O'Hagan (April 7, 1925 – January 2, 1991) was appointed the 22nd Fire Commissioner of the City of New York by Mayor John V. Lindsay on October 11, 1973 and served in that position throughout the Administration of Mayor Abraham D. Beame until he was replaced by incoming Mayor Edward I. Koch on January 17, 1978.O'Hagan joined the New York City Fire Department in 1947 at the age of 22, and quickly rose up the ranks.