Additional improvements and routine maintenance work were completed in the early 1910s . A greenhouse was built in 1910 , and the contagious-diseases ward on island 3 opened the following June . The main hospital was expanded in 1909 , the incinerator was replaced in 1911 , and a recreation center operated by the American Red Cross was also built on island 2 by 1915 . These facilities generally followed the design set by Tilton and Boring . When the Black Tom explosion occurred on Black Tom Island in 1916 , the complex suffered moderate damage ; though all immigrants were evacuated safely , the main building 's roof collapsed , and windows were broken . The main building 's roof was replaced with a Guastavino-tiled arched ceiling by 1918 . The immigration station was temporarily closed during World War I in 1917-1919 , during which the facilities were used as a jail for suspected enemy combatants , and later as a treatment center for wounded American soldiers . Immigration inspections were conducted aboard ships or at docks . During the war , immigration processing at Ellis Island declined by 97 % , from 878,000 immigrants per year in 1914 to 26,000 per year in 1919
Black Tom explosion
Black Tom explosion
Ellis Island