How does Chabad ‘explain’ the Holocaust? 

Beautiful! what an aidel way of speaking, from your words and mannerisms i can see that you are a true ben torah.

So true, bless Chabad!

In Likkutei Dibburim, the previous Rebbe warned before the war, that by leaving Tora observance, Jews were not only harming their souls, that they were also putting their material bodies in severe material danger. During the war, the previous Rebbe said that the events were above nature and the fulfillment of the Tochacha, and that the only salvation was Teshuva. That is why he published the Kria ve-haKedusha, to bring Jews back to Tora and thus save the Jews in Europe.

Excellent!!

He did not explain what to tell people whose relatives did not survive - why they did not survive.

The holocaust and all the tragedies over the past 2000 years were proclaimed by Hashem clearly in Jeremiah 23:25-32. Traditional Judaism doesn’t listen to His voice from heaven. Hashem brings peace and evil. Bava Metzia 59b:5

I'm gonna ask a legit question, were it not for the holocaust, would the state of Israel still have come to be? The problem with the holocaust, it had no precedent, thus it was as unforeseen as 10 unforeseeable things. Thus sayeth the Lord of Hosts, "Israel is the apple of my eye, I will bless those that bless you and curse those which curse you." God's will be done. ✌❤ from Canada Great talk, I had to watch it twice.