if hitler did not lose the war, i don't think today one jew would be alive. >> father patrick dubois is on a motion to find hitler's hidden killing fields. before him lies a continent of these mass graves and extermination sites, many of them are invisible. >> yeah, totally invisible. and under corn fields. under a field. yeah, yeah. >> many would never be recorded? >> never be recorded and still buried like animals. >> repor w republic of moldova where in one day he took us to four unmarked mass graves. in this field, he toemd , 60 jews. beneath this farm, 100. above this city, under this 1,000 body. do you think they're still here? >> yeah. yeah, they're still here. >> reporter: thousand of eyewitnesses, millions of and investigating have led him to more than 1700 execution sites. once in ukraine, under the supervision of a rabbi, and the >> officially a place where no jew had been killed. we found 17 mass graves. >> what did you find? y you see a mover with, holding his boy until the end. the boy tried to go out. you see thatanother one was, was buried alive. she had the mouth ope

for the past 15 years, father patrick dubois has been tracking for witnesses who are still alive. laura logan reports in a story for "60 minutes." >> the general order was to eliminate the last jew, even the baby, even the old mommy. they never left any body. >> a policy of total annihilation. >> annihilation. if hitler did not lose the war, i don't think today one jew would be alive. >> father patrick dubois is on a killing fields. before him lies a continent of extermination. these mass graves and extermination sites, many of them are invisible. >> yeah, totally invisible. and under corn fields. under house. under a field. yeah, yeah. >> many would never be recorded? >> never be recorded and still buried like animals. >> reporter: we traveled with the father to the former soviet republic of moldova where in one mass graves. in this field, he toemd us, 60 jews. beneath this farm, 100. above this city, under this hill, 1,000. 1,000 body. do you think they're still here? >> yeah. yeah, they're still here. >> reporter: thousand of eyewitnesses, millions of documents, and 15 years of