Not CO2:  <a href="http://www.google.com/search?client=safari&#38;rls=en&#38;q=gas+used+in+concentration+camps&#38;ie=UTF-8&#38;oe=UTF-8" rel="nofollow">http://www.google.com/search?client=safari&#38;rls=en&#38;q=...</a><p>2-3 hours to cremate:
<a href="http://ohiocrematory.com/process.html" rel="nofollow">http://ohiocrematory.com/process.html</a><p>"There were many mass graves identified"
The issue is the numbers involved.  6,000,000 to be exact.  
<a href="http://www.gmsplace.com/wp-content/uploads/2009/06/normandy-cemetery.jpg" rel="nofollow">http://www.gmsplace.com/wp-content/uploads/2009/06/normandy-...</a><p>"Can anyone seriously believe the surviving witnesses are victims of a collective hallucination or part of a conspiracy to hide some "truth"?"<p>Why even go there?  Simply investigate the "scientific" basis for accepting the given narrative.<p><a href="http://www.google.com/search?client=safari&#38;rls=en&#38;q=holocaust+revisionists+jailed&#38;ie=UTF-8&#38;oe=UTF-8" rel="nofollow">http://www.google.com/search?client=safari&#38;rls=en&#38;q=...</a><p>"It saddens me my species is capable of such a cold, directed, rational and efficient genocide. The possibility it may happen again frightens me deeply."<p>We're in agreement, here.  And we frankly don't even need to reach that far back in history for evidence of the vile in our species.  One look at what was done to Gaza and Iraq suffices.