Camp Verde, Arizona (CNN) -- Self-help guru James Arthur Ray "was in charge of all the activities" at the Arizona retreat where three people died in a purification ritual in 2009, a survivor of the event testified Tuesday.
Beverley Bunn, an orthodontist, has recounted seeing several people suffering obvious distress during the October 2009 "sweat lodge" during her time on the witness stand. But despite her medical training, she said, she didn't help them because Ray was "in charge of the sweat lodge."
"Mr. Ray was in charge of all the activities," Bunn said. "Mr. Ray is the expert, and that's who I was there to learn from. I felt if anybody was in jeopardy, he would be the one to actually take care of the situation or acknowledge it or ask for some type of help or assistance."
Ray is charged with manslaughter in the deaths of three people who took part in the sweat lodge, a ritual modeled on native American traditions. His lawyers have argued that the deaths were an accident, suggesting that exposure to an unknown toxin, perhaps a pesticide, could have caused the fatalities.
The sweat lodge was part of a "spiritual warrior" seminar in which participants paid up to $10,000 to seek "new areas of consciousness," another survivor, Stephen Ray, testified Tuesday. Ray, who is not related to the defendant, had attended several of his self-help seminars before -- but he said he was unaware a sweat lodge was part of the process until the morning before it happened.
Before the participants went into the hut, James Ray told them, "You might feel like you're going to die, but you're not," several witnesses have testified.
Stephen Ray said that when several people passed out, James Ray said, "We'll get them after the round is complete." And Bunn said she didn't help because "I wasn't in control of the sweat lodge," Bunn said. "I was also trying to survive it myself."
The lodge was made of willow trees and branches, and covered with tarpaulins and blankets -- was heated to perilously high temperatures, causing the participants to suffer dehydration and heatstroke. But during a recorded talk to his followers, Ray repeatedly warned them to drink plenty of fluids.
Stephen Ray said said the lodge was "uncomfortably warm" from the beginning, and the wave of steam from water being poured over heated stones "was so hot I covered up my nose and my mouth." The sometime long-distance runner said he tried to endure it because "I didn't want to be a failure," but eventually, he said, he tried to feel his way out of the tent.
"The last thing I remember is feeling my way and than passing out. It goes blank from that point ... The next thing I remember, I'm in the hospital," he said.
Stephen Ray was in a coma for several days after the sweat lodge. His medical records indicate the doctors thought it was from exposure to a poison, not heatstroke, but he testified that his toxicology tests were negative. And under cross-examination, Bunn said she had been beset by a large number of ants while on a "vision quest" -- a 36-hour desert fast -- in the days before the sweat lodge.
Bunn's roommate, 38-year-old Kirby Brown, of Westtown, New York, died that night. So did James Shore, 40, of Milwaukee.
Volunteer Lizbeth Marie Neuman, 49, of Prior Lake, Minnesota, died nine days after the ceremony. At least 15 others who took part in the ritual fell ill, but more than 40 others were uninjured.
In Session's Beth Karas and Grace Wong contributed to this report.