Winsor McCay's 1918 animated documentary recreating the 1915 sinking of the British liner.

Public domain (US): Published 1918; all works published in the US before 1931 (and foreign works published before 1931) are public domain in the US (95-year term expired). Source: Internet Archive (https://archive.org/details/silent-the-sinking-of-the-lusitania).