One woman died after she was left on the floor of her hospital room, overdosed by poorly trained staff.
Others died in ambulances on long journeys to emergency rooms because local facilities were closed for being such a mess.
Witness after witness at a Senate hearing Wednesday begged the federal government to properly fund the neglected Indian Health Service, and even government officials in charge of the service said they were struggling to get the resources they need.
"What we've found is simply horrifying and unacceptable. In my view, the information provided to this committee and witness first hand can be summed up in one word: malpractice," Wyoming Republican Senator John Barrasso, who chairs the Senate Committee on Indian Affairs.
"The Centers for Medicare & Medicaid Services — another agency within the Department of Health and Human Services — has confirmed not only that these same problems continue to fester, but that they pose immediate risk to patient safety," Barrasso added.
"In fact, they have led to multiple patient deaths."
One of those deaths was Debra Free, who died in the Winnebago Hospital in northeastern Nebraska in 2011.
"Since at least 2007, this IHS facility has been operating with demonstrated deficiencies which should not exist at any hospital in the United States," Free's niece, Victoria Kitcheyan, told the committee.
"I am not talking about unpainted walls or equipment that is outdated," Kitcheyan, who is treasurer of the Winnebago Tribe of Nebraska, said.
"I am talking about a facility which employs emergency room nurses who do not know how to administer such basic drugs as dopamine; employees who did not know how to call a Code Blue; an emergency room where defibrillators could not be found or utilized when a human life was at stake; and a facility which has a track record of sending patients home with aspirin and other over-the-counter drugs, only to have them airlifted out from our Reservation in a life threatening state."
Free died at age 45 after suffering a heart attack, her obituary noted.
"According to what our family learned, Debra [Free] was overmedicated and left unsupervised, even though the nursing staff at the Hospital knew that she was dizzy and hallucinating from the drugs and should be watched closely," Kitcheyan testified.
"After her death, a nurse at the hospital told my family that Debra had fallen during the night. She said that that nurses from the emergency room had to be called to the inpatient ward to get Debra back into bed because there was inadequate staff and inadequate equipment on the inpatient floor to address that emergency," she added.
"While the hospital insisted that they did everything possible to revive her and save her life, we question just how long she remained on the floor and what actually happened. My Aunt Debra Free left behind a nine-year-old daughter and a loving family. She should not have been allowed to die like this."
The U.S. has an agreement dating back to 1787 that requires the federal government to provide American Indians with free health care on reservations.
But the Indian Health Service only has about half of the money it needs, and poor tribes in some of the most remote areas have underfunded facilities and substandard care, critics say.
"The administration is responsible for providing and delivering health services to American Indians and Alaska Natives across the country. Their federal obligation mandates that they promote health and safe Indian communities while honoring tribal governance. This is not happening," Barrasso said.
Some rich tribes that run casinos supplement their medical care, but tribes in the upper Plains states are in remote areas with little opportunity to generate extra income.
William Bear Shield, a representative of the Sioux Tribe of South Dakota, said they have organized numerous meetings with the Indian Health Service to try to improve matters.
"We have been voicing our concerns and demanding to be involved. We have been saying that the current situation was going to occur and wanted to prevent it. We went unheard." Shield told the hearing. He said the IHS closed a local emergency room because it was run so badly, but did not provide an alternative, and at least one tribe member died of a heart attack in an ambulance en route to a facility 70 miles away.
"The IHS is severely underfunded compared to other federal agencies," said former Senator Byron Dorgan, chairman of The Center for Native American Youth at The Aspen Institute.
"You may have heard the phrase 'Do not get sick after June,' because if you do, you will not be able to get care. This, to me, is a rationing of health care — care that is guaranteed by treaty. If we start funding IHS at levels commensurate with need, I believe we will solve a lot of the issues revealed in the 2010 report and the ones occurring elsewhere in this country," Dorgan added.
Robert McSwain, principal deputy director for the HIS, says the agency is working to solve the problems but said it's hard to provide services in rural, isolated communities. It's also hard to recruit and keep staff to work in these communities. "HIS is addressing issues such as recruitment and retention in innovative ways, such as utilizing tele-medicine, including tele-radiology and tele-behavioral health," he said.
Mary Wakefield, acting deputy secretary of the Department of Health and Human Services, admitted the service was struggling.
"We know that more needs to be done to ensure quality health care is provided by IHS," Wakefield testified.
She said Mary Smith, who is an enrolled member of the Cherokee Nation, was now deputy director of the HIS and Dorothy Dupree, a member of the Fort Peck Assiniboine Sioux Tribes, was named deputy director for quality health care.
This article first appeared on NBCNews.com.