Another story I heard from Shlomo was about Moshe Leib Sassover. When he passed away, he was tried by the Heavenly Court (the "Beis Din shel Lemayla") and was found that he merited to go to heaven.
In order to go to heaven, they rush you through hell first. You got fast and then you get to heaven.
But Moshe Leib Sassover saw all the broken and tortured people in Hell and he said that he was going to stay with the people in hell.
The escorts tried to reason with him and told him that he was a righteous person and his place was in heaven not in hell, but he wouldn't hear of it. So he tried to make a deal.
He wanted all of the people who were in hell to go with him to heaven. There are two endings to this story.
The first ending is that the Beis Din decided that if he always did a favor, a mitzvah, for someone whenever he had the opportunity then he was the person to redeem all these souls. But if he passed even once, then he wasn't the person to get the souls out of hell. But he did the favors so he got the people out.
But the sad thing is that hell was soon filled up all over again anyway.
The second ending was that just as many mitzvahs as he did for others is the number of people he could get out of hell. So the lesson is that when do do a mitzvah, you redeem a person from hell.
In this story I'm under the impression that hell is a permanent place at least for some people.