Initially there was no system in place to allow prisoners to send letters ; censorship arrangements were made through the Dominion Police in Ottawa , and the American Consul was designated a representative for prisoner welfare . As the war progressed , groups of detainees were transferred to and from other prisons according to their behaviour or level of risk and the number of inmates per institution . After the 1917 Halifax Explosion , prisoners were transferred to the 800-man Amherst Internment Camp at Amherst , Nova Scotia . One of the prisoners transferred may have been Leon Trotsky , although this is disputed
Halifax Explosion
Halifax Explosion
Melville Island (Nova Scotia)