The participants were on a so-called spiritual retreat organized by self-help guru James Arthur Ray. Each had paid $9,000 to attend.
However, something went wrong in the sweat lodge, leaving three people dead.
Relatives of Kirby Brown, who lost her life on the retreat, spoke out on "The Early Show" about the sweat lodge and Ray's alleged involvement in the tragedy.
Robert Brown, Kirby's brother, said his sister didn't know what she was getting herself into.
"I think that she went there with all the right ideas and purposes in mind to better her life, to better herself. She had big plans," he said.
And while Kirby had attended Ray's seminars previously, Robert said, they were in classroom-like settings for information and networking -- not the physical kind of retreat she attended this time.
Tom McFeeley, her cousin and family spokesperson, said something went "horribly wrong" in the sweat lodge.
McFeeley said, "We've talked to many people in the lodge. And what we found out is that it was a very confusing scene because people were passing out and coming to. There were a lot of people who wanted to leave the tent, wanted to leave the lodge, but when people could leave was controlled by James Ray."
Ray, McFeeley said, was at the door.
"You could you only leave after each session, this was about 15 minutes, and he controlled when the session was over and how long that door stayed open, so we believe there were very dangerous decisions made by him about when people were allowed to exit, re-enter to help other people out," McFeeley said. "We have very serious concerns about those questions."
McFeeley added that Ray was inadequate to do the things he did on the retreat.
"I think when you see someone who writes books and has CDs and has been on 'Oprah,' I think you make an assumption about their qualifications," he said.
McFeeley said he believes three people who died in the sweat lodge were "definitely murdered."
"There's no question they were murdered," he said. "We think it's lucky that 52 other people survived. What they did to them through sleep deprivation and a 36 hour fast, and they came off the fast with a breakfast buffet like it was the Holiday Inn. This is not the way do you these physical things."
McFeeley said Ray was playing "very dangerous and trying physical games."
"He was literally putting people's lives at risk and he should have seen signs," McFeeley said. "There were other people who got sick at other events in previous years."
Robert saud remembering his sister and never having this happen again is what's on his mind now.
"I want people to know my sister, you know, the truly beautiful, inspirational, unbelievable woman that she was. She was everybody's best friend," Robert said. " ... Nobody should be going through what we're going through right now. She was taken from us. I want her back."
However, though his family knows Kirby isn't coming back, he said, they're hoping now that the other victims get the professional counseling they need to get through this "traumatic experience."