History
Lieberman was one of S.H.I.E.L.D.'s newly recruited super-soldiers of the Reserves. Unlike the other Reserve members, who depend on using their costumes as the source of their powers (with the exception of the Goliaths), Lieberman's powers and abilities were completely innate, due to taking the Super-Soldier Serum. Lieberman was surprisingly briefed and shown by Nick Fury that he was potentially destined to replace Captain America if he ever died, or in some other cases in which Lieberman was very hesitant to fill in. On a night out with the Reserve members, Lieberman was involved in a fire scene and bravely rescued fifty-seven fire victims, but after saving them, he suddenly died. His body was taken back to the Triskelion and privately examined. The cause of his death was determined to be due to his nervous system collapsing from the strain of the Super-Soldier Serum.
However, Lieberman's ascension to become (and replace) Captain America and his sudden death wasn't the first time that S.H.I.E.L.D. had tried to replicate super-soldiers like Captain America, and that several other candidates like Lieberman perished with similar results.[1]