In Chicago on Saturday, there were answers for a group of people who were on both sides of those questions.
Hotel workers Gregory Frederick and Arnulfo Ponce were greeted by the women they saved -- Leigh and Faye Gilmore.
"It's overwhelming. I mean, i can't imagine her being here," Frederick said. "After eight years, our all being here together, 'cause I didn't think she had made it."
The mother and daughter had checked into the Marriot World Trade Center September 10 for their visit to New York. They were to attend a friend's art exhibit.
When the planes hit, the pair found themselves marooned on the hotel's fifth floor with no passenger elevator to take Leigh, who lives with multiple sclerosis, down to safety. Her mother would not leave her.
"To see her there, I was hoping that she wasn't there. But to see her waiting, I was horrified by that. But just to get them out of there, that was our main objective, to get them out of there," Frederick said.
Gregory came for them at the insistence of his boss, who had recalled that someone in a wheelchair was likely stranded in their room.
"I can't stop smiling," Faye Gilmore said. "I'm just so happy to see these guys."
With Ponce's instruction, Frederick got the ladies, who were with a friend, down to the street on a freight elevator that was still running. Moments later, one of the towers collapsed onto the hotel, and a world of pain descended.
"I put it away," said Ponce. "I put it away in a chest, and I didn't open it until now again. There are other things I kept in the chest, and I'm glad I was able to open this because it's a positive feeling and I'm glad now it's a joy."
It was a joy like, perhaps, when Leigh Gilmore saw angels come to rescue her.
"I'm just so happy to see them," she said. "After they were in my brain when I got through all of the 9-11 thing, I always wondered, but now I know."
"That's why I had to come here today, because I wanted closure," Ponce said. "I feel like these are part of my family now."
The way the Gilmores escaped with their lives resulted in an improvements for people with disabilities. Leigh Gilmore helped get laws changed at the city and state level to mandate that evacuation plans focus on the needs of the disabled in certain kinds of high-rises.