In late December 2015, Jose Azurdia an immigrant detained by Immigration and Customs Enforcement at a facility in San Bernardino, California got sick and began vomiting. When a half-hour later an officer told a nurse of his condition, the nurse responded that she did not want to see [him] because she did not want to get sick, according to a new report from human rights groups .

After a series of other delays in getting Azurdia care including time wasted in getting him to the facilitys medical unit, even after officers had been notified of symptoms indicating a heart attack, from his left arm going numb to trouble breathing and pain in his shoulder Azurdia finally got to a hospital over two hours after officers were first told he was sick. His heart was too damaged to respond to treatment, per the report. He died in the hospital four days later.

Azurdias case is one of several immigrant deaths in ICE custody highlighted in the report from Human Rights Watch, the American Civil Liberties Union and other groups. For the report, released Wednesday, independent medical experts analyzed ICEs publicly released detainee death reviews for 15 cases of immigrant deaths in detention from December 2015 to April 2017. (For one other death that occurred during that period, ICE still has not publicly released a review.)

In more than half of the deaths, or 8 out of 15 cases, the physicians found that inadequate medical treatment had likely contributed or led to detainees deaths. The medical experts also found evidence of substandard care in nearly all of the cases.

In Azurdias case, physicians found that his death was likely preventable with one doctor characterizing the nurses refusal to see him as egregious.

While such cases represent just a small fraction of the hundreds of thousands of people who passed through ICE detention during that time ICE held an average of 40,500 people per day in 2017 alone, per HRW the deaths still raise serious concerns about what the report calls serious deficiencies in medical care in many of ICEs detention facilities. Several immigrants deaths had come after unreasonable delays in providing care, botched emergency responses and poor quality of care by officers and medical staff, according to the report.

Deaths are the tip of the iceberg in terms of poor medical care and conditions, HRWs Clara Long, co-author of the report, told HuffPost on Monday.

Deaths are tragic anyone who dies needlessly because of government negligence or abuse is reason to be concerned, she said. But they also indicate a broader class of 40,000 people a night exposed to the same conditions.

In a statement to HuffPost, an ICE spokesperson said the agency takes very seriously the health, safety and welfare of detainees and that any death in ICE custody was a cause for concern. The agency also noted that each death is reviewed internally, per protocol, with reports sent to ICE leadership and the Department of Homeland Security.