Leon Sawchuk was a Human man, a Starfleet officer assigned to the command division of the Federation starship USS Enterprise under the command of Captain James T. Kirk in the 2260s.
History[]
While Sawchuk was at Starfleet Academy, he met and fell in love with Tommy Carter. They maintained a steady relationship, and eventually both served together aboard the Enterprise.
In 2269 or 2270, Carter drowned when the Enterprise was flooded by Ulum near Polymax VIII. Sawchuk was grief-stricken, but James T. Kirk gave him focus, recommending that he take the body to sickbay and then try to prevent as many others from drowning as he could. (TOS comic: "What Pain It Is to Drown")