A mother of eight children who was living at a large homeless camp in south Minneapolis died of an apparent drug overdose early Sunday, marking the third death in less than a month linked to the crowded camp.

Pamela Sue Rivera, 51, was found unconscious and alone in her tent early Sunday, and a friend immediately began performing CPR, relatives said. Paramedics gave her 10 doses of Narcan, a drug that can reverse the effects of opioids, in her tent and in the ambulance on the way to Hennepin County Medical Center. She died there at 4:29 a.m. on Sunday, according to the Hennepin County medical examiner.

The cause of the death is still under investigation.

Despite an intensive outreach effort by American Indian and local health agencies, heroin and methamphetamine use remains common at the encampment, near the Little Earth housing development, and overdoses are an almost daily occurrence, residents and health workers say.

Natives Against Heroin (NAH), a street outreach group that has been patrolling the encampment, reacted swiftly and forcefully to the latest fatality. On Sunday morning, a dozen volunteers with the group marched through the camp while pounding drums and shouting, "Shut it down!" They stopped outside three large tents that they said had been home to at least six people who were believed to be selling heroin at the camp.

Without warning, they ripped the tents out of the ground, yelled "Everybody out!" and threw all the belongings in a giant pile near the center of the encampment. A small crowd gathered to watch and burn sage as sleeping bags, tarps, mattresses, coolers, bicycle tires and camp chairs were hurled into the air, according to a video of the incident posted on Facebook. Two men crawled out of tents while they were still being torn apart, and they were ordered off the grounds by NAH's security crew.

Family members of Pamela Rivera, 51, gathered at the Little Earth housing complex to mourn and honor her memory.

"This is what happens when people die!" yelled Greg Franson, one of the leaders of Natives Against Heroin, as he angrily tore at one of the tents. "When people die, you gotta man up and take care of it."

James Cross, the founder of Natives Against Heroin, yelled, "You kill our people! You gotta go ... We ain't playin' out here."

The confrontation revealed the growing tensions and frustrations among many inhabitants, who say groups of drug dealers are infiltrating the site and preying on vulnerable people struggling with substance-use problems.

In recent weeks, the encampment has become more divided: One end consists mostly of families with children, while the other end (nearest to East Phillips Park) appears to have more drug use and altercations. Some families said they have become afraid to venture to the other side of the encampment after dark because it is frequented by drug dealers.

A few hours after the confrontation, friends and relatives of Rivera gathered for a sacred ritual at a relative's home in the Little Earth housing complex nearby. They built a "spirit fire" in Rivera's honor using wood from the camp. As two girls pounded ceremonial drums and chanted, four bald eagles appeared, one by one, in the sky above Little Earth and began circling the area in wide loops. Yolanda Rivera, 22, a daughter of Rivera, and other relatives raised their hands toward the eagles as the drums pounded.

Yolanda Rivera said her mother became homeless in June after she was evicted from her apartment in Little Earth for "keeping company with the wrong people," she said.

It was the first time that Rivera was unable to find a place of her own; soon after, she moved into a tent at the encampment near Hiawatha and Cedar avenues in late July, becoming one of the camp's first inhabitants. Yolanda said her mother had a difficult time adjusting to being homeless, and her depression and drug use intensified after she moved to the encampment.

"The stress of living at the camp was overwhelming, and [drugs] became her way of coping with it," said her son, Orlando Rivera, 22.

Even so, her fatal overdose came as a shock to family members. On Friday, Rivera told her children that she had finally been placed on a waiting list for low-income housing after weeks of searching with the help of social workers. The evening before her death Rivera seemed cheerful as she picked through donated clothing at a large tent operated by Natives Against Heroin, relatives said.

"It's so tragic because my auntie had such a generous heart," said Trinity Bellanger, 19, a niece of Rivera, who said she recently moved to the homeless camp to escape drug and alcohol use on the White Earth Indian Reservation.

A burial ceremony is planned for Rivera at 1 p.m. on Saturday at the new Pine Point School in Ponsford, Minn., on the White Earth Indian Reservation. Rivera is survived by five sons and three daughters, as well as six grandchildren.

Chris Serres • 612-673-4308 Twitter: @chrisserres