In May, Ukrainian workers laying a gas pipe in a southern village dug into a buried chamber of thousands of Jews killed during the Holocaust. That same month, a construction crew building a new office complex in western Ukraine burrowed into the corpses of several dozen more Jews. Stumbling upon such mass graves is not particularly unusual in Eastern Europe. Less well known is how many more "martyr sites" lie undiscovered and unmarked in fields and forests across the region -- wherever mobile Nazi killing units scorched the earth in the so-called "Holocaust of bullets." It seems momentum is growing in the search for such sites.