During her nearly three days at an Arizona drug detox center, law enforcement reports show, an Ohio mother repeated the same request to multiple staff members: Take me to the hospital.

Madison Cross, 22, traveled from her home outside Columbus, Ohio, last Oct. 7 to check into Serenity Care Center, a state-licensed drug detoxification center in suburban Phoenix. Her family said she wanted to kick her addiction to opioids and other drugs for her 2-year-old daughter.

Once at the center, she showed escalating signs of distress.

She had trouble breathing. Her pulse raced. She was wheezing, and her lungs sounded “crackly," staff members told investigators.

She appeared lethargic and ill. One technician told investigators her complexion was jaundiced, and her lips were purple. Another said she went from pale to yellow to blue.

Technicians reported her vital signs to nurses, who consulted with medical staff about her care, according to medical records from the Maricopa County Sheriff's Office obtained by USA TODAY under a public records request. She was ordered several medications.

But she was not sent to the full-service hospital less than a mile away. She collapsed in her room at Serenity and was soon pronounced dead.

The Maricopa County medical examiner concluded Cross’ death was an accident caused by “septic complications of acute bronchopneumonia in the setting of heroin toxicity.”

An attorney representing the young woman's family called the center's treatment of Cross "outrageous."

"This woman was basically begging for them to save her life by sending her to the hospital, and they refused," attorney John Wrona told USA TODAY.

He plans to file a lawsuit on behalf of the family.

A spokesman for Serenity said the center provided appropriate care and monitoring for Cross. The center performs regular room checks, vital signs readings and intervenes when required, spokesman George Haj said.

Patients who are undergoing withdrawal and trying to stay clean are particularly vulnerable to medical emergencies. As the opioid epidemic causes demand for addiction treatment to surge, industry veterans said tougher standards, better screening and greater oversight are needed to improve patient safety.

More than 1.4 million people sought treatment for alcohol or drug addiction from inpatient, outpatient and residential treatment programs in 2015, according to the Substance Abuse and Mental Health Services Administration. The federal agency recorded 3,362 deaths.

States separately report death investigations at residential treatment centers. In California alone, state regulators have investigated more than 150 deaths at treatment facilities since 2014. That includes 44 during the fiscal year that ended June 30.

Industry officials said the for-profit centers that have flooded the growing market for addiction treatment are in some cases providing aggressive marketing and substandard care.

"This is a huge issue for the industry," said Marvin Ventrell, executive director of the National Association of Addiction Treatment Providers. "It is a critical time where we can get this right or we can get this wrong."

Ventrell was speaking generally. He was not addressing Cross' death, Serenity or any particular center.

His organization, which represents about 850 facilities in the USA, tightened its policies this year to require members to adhere to an updated code of ethics that prohibits such practices as "patient brokering" – paying recruiters to bring in patients who can generate lucrative insurance payments for services that must be covered under the Affordable Care Act.

The association is cracking down on websites that deceive consumers about treatment as well as inducements to get people in treatment.

Unscrupulous providers try to sell the service to the prospective patient, industry leaders said, rather than assessing his or her individual medical needs. Many patients, leaders said, might fare better if they received medications such as suboxone or methadone from a doctor rather than checking into a facility and detoxing.

"The key is not to be assessed by a marketer on a website but by a clinical provider at a reputable center," Ventrell said.

More:Mom who lost 2 sons in 1 day to opioids: Give kids a life-saving exit strategy

More:Senate advances plan to combat opioid epidemic

More:Naloxone can reverse opioid overdoses, but does the drug belong in elementary schools?

More:The opioid crisis hits home. Mine.

The burgeoning industry has attracted the attention of congressional investigators. The House Energy and Commerce Subcommittee on Oversight and Investigations called industry leaders to a hearing in July on advertising and marketing practices.

Longtime treatment organizations said they welcome tighter regulations for an industry flooded with newcomers seeking to profit off the addiction crisis.

Mark Mishek, president and CEO of Hazelden Betty Ford Foundation, told lawmakers that the industry is underregulated and lacks consistent quality standards.

"Our industry has seen the rise of unprofessional, unethical and sometimes illegal practices such as deceptive marketing and patient brokering – not to mention excessive consumer billing and insurance fraud," Mishek testified. "In too many cases, people who need help are instead being harmed."

More people need addiction treatment than there are beds or outpatient facilities available. A federal Substance Abuse and Mental Health Services Administration report estimated about one in 10 people who needed substance-abuse treatment in 2016 received it.

Advocates said for-profit treatment centers provide Americans much-needed access to care. They said it's inaccurate to say bad business practices have led to poor care at for-profit centers.

Mark Covall is CEO of the National Association of Behavioral Healthcare, an industry organization that represents about 1,000 nonprofit and for-profit members that provide inpatient, outpatient and residential treatment for mental health and substance abuse.

Covall said association members adhere to state licensing requirements and often are scrutinized by third-party accrediting organizations such as the Joint Commission and the Commission on Accreditation of Rehabilitation Facilities.

"For-profit or nonprofit is a tax status," Covall said. "That doesn't necessarily give any indication of how well or not well a provider is doing."

'A lot of the problems we see come from the business model'

When Shaun Reyna contacted a Murrieta, California, treatment center in 2013, he was told he would receive a medical detoxification, an attorney for the family said in a lawsuit.

Reyna, battling alcohol and benzodiazepene addiction, was desperate for help, attorney Jeremiah Lowe says.

"I feel like I can't hold on any longer," Reyna said in a recorded conversation with a company employee.

"I get it, brother. I get it," the employee responded. "We're reaching crisis mode ... you need to get into a safe environment."

He took a train from his Atwater, California, home to A Better Tomorrow, the treatment center. He was admitted, and left unattended in his room. He slashed his arm, chest and neck with a razor and bled to death.

Reyna's family sued American Addiction Centers Inc., the publicly traded company that owned A Better Tomorrow. In February, a jury awarded the family $7 million in damages.

American Addiction Centers denies it is responsible for Reyna's death. It has appealed the judgment.

The company closed the Murrieta facility in 2017 as part of a consolidation.

Cody Arbuckle died at a Las Vegas addiction treatment facility owned by AAC last July. A coroner listed the cause as toxicity from loperamide, an ingredient in the anti-diarrhea drug Imodium A-D.

His mother has filed a lawsuit against AAC in the Clark County District Court. Kathryn Deem, Arbuckle's mother, is represented by Jeremiah Lowe's San Diego law firm, Gomez Trial Attorneys.

According to Deem's attorneys, staff at the Solutions Recovery house reported that Arbuckle was under the influence of drugs. But rather than transporting him to a hospital, they say in a lawsuit, they sent him to a "non-medical residential detoxification house" in Las Vegas.

Arbuckle was supposed to be under 24-hour monitoring, the lawyers say in the lawsuit, but he was not checked over 14 hours overnight. He was found dead the following morning.

The lawyers say in the lawsuit that AAC kept Arbuckle "in their non-medical program for business reasons, because they did not want to let go of their paying client."

He became the seventh patient who died shortly after entering an AAC facility, the attorneys say in the lawsuit.

Attorneys for AAC filed a motion to dismiss that lawsuit and compel arbitration, and the court has scheduled a hearing for Oct. 30. Arbuckle, like other patients, signed an arbitration agreement when he entered detox.

Attorneys for Arbuckle's mother say they will argue that the agreement is not enforceable, in part, because patients entering detox are vulnerable.

AAC representatives would not respond to USA TODAY's questions about the Arbuckle and Reyna cases, citing federal patient confidentiality laws.

'We are using this data to improve our services'

Company officials said AAC facilities are accredited by the Joint Commission or the Commission on Accreditation of Rehabilitation Facilities and meet or exceed the licensing requirements of the states in which they're located.

Tom Doub, AAC's chief clinical officer and chief compliance officer, said in a statement that AAC seeks "to set a standard in reporting quality outcomes."

The company paid for a study by Centerstone Research Institute that surveyed former AAC patients. Of those former patients, 63 percent maintained abstinence one year after treatment, a higher mark than national benchmarks, according to Doub.

"As we prepare for the next phase of research, we are using this data to improve our services as part of our ongoing commitment to clinical excellence," Doub said.

Lowe says the Reyna and Arbuckle cases represent a larger phenomenon in the industry.

"A lot of the problems we see come from the business model that allows for big profiteers to come in and make a whole bunch of money off the most vulnerable population," he said.

Six minutes, 25 seconds

Video footage taken in Cross' small detox room during the early morning hours of Oct. 10, 2017, shows her struggling.

She attempted to open a restroom door but seemed confused. Legs wobbling, she stumbled away from her bed and fell to her knees. She grabbed a shelf and held on for several seconds. Her right arm dangled to her side. She collapsed to the floor and lay still.

Six minutes and 25 seconds passed before a Serenity employee entered the room. The technician took her pulse – there was none, medical and sheriff's reports showed – rolled her on her back and began chest compressions.

Paramedics arrived minutes later and took her to Banner Del E. Webb Hospital, blocks away on the same street.

Efforts to revive her were unsuccessful. She was pronounced dead at the hospital.

Joshua Michael Kennedy, the technician who discovered Cross' body, was interviewed by sheriff's investigators that morning. Serenity's attorneys listened to the interview over the phone.

Kennedy said Cross asked to be sent to the hospital because she didn't think she was getting the medication she needed. She worried she might have contracted strep throat from her daughter, investigators wrote.

Kennedy took her vital signs at 3 a.m. He noted an elevated pulse rate and less-than-ideal blood pressure, investigators wrote. He reported this to nurses at Serenity, but he "felt as if their response to him was as if he were being a nuisance," the investigators said.

Wrona, the family's attorney, argued that Serenity's nurses failed to recognize the seriousness of Cross' condition soon enough. He said the problem was compounded by a policy that limits communication from family members during detox.

"There is a difference between someone who is going through a garden-variety detox and one who has a life-threatening medical condition," Wrona told USA TODAY. "If they had spoken to her family, they would have been able to advocate for her in some way."

Haj, the Serenity spokesman, said privacy laws prohibit the center from discussing the details of Cross' case.

"Our policy is that medical personnel constantly monitor a patient’s condition ... including regular in-person monitoring of vital signs and in-person room checks," he said.

Staff members "do not rely solely on the video feed," he said.

"Patients undergoing withdrawal frequently request transfers to hospitals in the hopes of relieving anxiety or in the hopes of obtaining drugs," Haj said. "If all requests are satisfied, a patient’s substance use disorder treatment can be severely hampered. Patients are monitored to see if medical intervention is required."

Haj said Serenity has treated 2,472 patients since opening in May 2016; Cross is the only patient who died in the center's history.

The state of Arizona cited Serenity Care Center for a deficiency in how it screened a patient arriving at detoxification on the night of Oct. 7.

The Arizona Department of Health Services, the state agency that licenses and regulates detox facilities, did not name the patient, but the time of intake and description matched details of Cross' arrival and condition.

According to Arizona's notice of deficiency, Serenity's policies require a registered nurse to assess a new patient's medical condition and history. Two Serenity employees said that a licensed practical nurse, not a registered nurse, conducted the screen and assessment, according to state health department records.

Serenity was not fined by the state. The company submitted a plan of correction in May that detailed how the facility would address intake screening.

'He had been clean'

Fernin Eaton says his son had struggled with addiction on and off since he was a teenager. But he was hopeful when Nathan entered the Center Point residential treatment home in San Rafael, California, in 2013.

"He had been clean," Eaton said. "He had not been using. It was a huge success."

While at the home, Nathan Eaton complained of a toothache. He left the home to go to a dentist's appointment, but he didn't make it there. He met his girlfriend instead and took two methadone pills, according to Center Point staff reports obtained by the family. He didn't feel better, so he took three more.

Fellow residents at Center Point recognized that he was high and urged him to notify the residential facility's managers.

Rather than sending him to a drug-detoxification center or a hospital, staff chose to keep him at Center Point. His body was discovered in his room the next morning, according to the Center Point staff reports .

Fernin Eaton received a call from a Center Point representative informing him that his son had died from a drug overdose.

Eaton thought his son had merely relapsed.

Three years later, he learned the details from the father of the Center Point resident who discovered Nathan Eaton's body.

'Large number of deaths at drug rehab facilities'

Paul Schraps, who runs the nonprofit Parent Teen Bridges to help families coping with addiction, requested information about Nathan Eaton's death, the autopsy and the facility's licensing. He shared it with Fernin Eaton.

Eaton filed a wrongful death lawsuit. Center Point Inc. paid $245,000 to settle the case. It did not admit liability.

Schraps has since probed several other deaths at addiction-treatment centers. He's convinced it's a national problem.

Schraps said overloaded medical examiners don't have the resources to adequately investigate deaths at addiction treatment centers, and state regulators often fail to conduct comprehensive inspections and investigations.

"We all know there's an opioid epidemic," Schraps said. "What most people don't know, there are a large number of deaths at drug rehab facilities."

Ventrell, of the addiction treatment industry group, says treating a person with substance abuse disorder is fraught with risk.

"This disease is so deadly," Ventrell said. "There are many good centers that follow good protocols and have had patients die in their care."

Tips for choosing an addiction treatment center

• Avoid centers that use high-pressure sales tactics.

• Be careful when searching online. Do not decide solely from online directories, generic websites or offers of free treatment placement through a toll-free number.

• Avoid centers that offer incentives such as free airfare.

• Be wary of facilities that don't contract with major insurance companies. They may bill excessively as out-of-network providers.

• Ask a doctor or other medical provider for a recommendation.

Source: National Association of Addiction Treatment Providers, USA TODAY research