With construction beginning in 1837, the Old Croton Aqueduct was a response to devastating fires and epidemics in New York City, which lacked adequate clean water. Irish immigrant laborers carried out much of the demanding work. Supplying New York City until 1955, part of the historic Aqueduct reopened in 1987, continuing to provide water to Ossining. However, the Aqueduct's intended capacity quickly proved insufficient for New York's rapidly expanding population. Just a few miles east, the much larger New Croton Aqueduct, engineered by B.S. Church, opened underground in 1890 with triple the capacity, still supplying New York City today.