Camp Verde, Arizona (CNN) -- Several participants in a 2009 "sweat lodge" ritual that left three people dead were collapsing and "having issues" in the superheated environment, a survivor testified Thursday in an Arizona self-help guru's manslaughter trial.
"I mentioned several times that I thought people were having issues and needed help to leave, and they didn't wish to leave," Melissa Phillips testified. She said she could hear "a snorting breath sound" from one of the participants, Kirby Brown, who died after the October 2009 event.
Phillips said during the event, one of her friends had collapsed "and couldn't feel her legs, and her husband was really concerned. So I asked the angels to help me and I did the breathwork affirmations that I was taught."
Phillips was the first witness in the trial of James Arthur Ray, who faces reckless manslaughter charges stemming from his "Spiritual Warrior" retreat outside Sedona, Arizona.
The sweat lodge hosted a purification ritual for participants modeled on Native American customs. Prosecutors argued that the lodge -- made of willow trees and branches, and covered with tarpaulins and blankets -- was heated to a perilously high temperature, causing the participants to suffer dehydration and heatstroke.
Brown, 38, of Westtown, New York, and James Shore, 40, of Milwaukee, died the night of the October 2009 event, while Lizbeth Marie Neuman, 49, of Prior Lake, Minnesota, died nine days later. At least 15 others who took part fell ill, but more than 40 others were uninjured.
Ray, 53, had conducted his Spiritual Warrior Retreat for six years at a cost of about $10,000 to participants. The sweat lodge, 5 feet tall and 23 feet wide, was built to accommodate up to 75 people. There was a pit in the center where heated rocks were placed, and Ray poured water over the stones to create steam.
Defense attorney Luis Li told jurors as the trial began Tuesday that the deaths were "a tragic accident -- not a crime." But prosecutors maintain Ray psychologically pressured participants to remain in the lodge even when they weren't feeling well, contributing to their deaths.
Under cross-examination, Phillips acknowledged signing a release form that warned of an "inherent risk" of injury in some activities in Ray's program. But she said she wouldn't have taken part "if I had thought my life could be in jeopardy." She also said she had left the lodge at one point, but went back in.
When she finally left, "I couldn't walk immediately. and I was shaking and I was overheated and not feeling well," Phillips said. Paramedics had been called by that time, and when one told her she may have suffered carbon monoxide poisoning, "I freaked out."
"I decided I had medical insurance and would go to the hospital and get checked out," she said.
In Session's Monique Oliver contributed to this report.