Story highlights Inadequate medical care contributed to eight detainee deaths from late 2015 through mid-2017

The majority of cases reviewed show substandard care in detention centers

(CNN) Among 16 immigrants deaths in US government detention centers between December 2015 and April 2017, half resulted from inadequate medical care for detainees in times of need, a new report finds.

The report , published Wednesday, examined 15 of the deaths, which had "detainee deaths reviews" released by US Immigration and Customs Enforcement during this time period. In eight of those deaths, the reviews found a lack of satisfactory medical care which, in turn, contributed to the deaths.

One detainee, Jose Azurida, 54, died of a heart attack. According to the report, a guard immediately alerted a nurse when Azurida began experiencing symptoms, including vomiting and numbness in his arm. But he was not taken to a hospital for two hours. Once there, his heart was too damaged to respond to treatment and he died four days later.

Evidence of substandard medical practices was also identified in six of the remaining death reviews, according to the report by Human Rights Watch, the American Civil Liberties Union, Detention Watch Network and National Immigrant Justice Center.

"ICE has proven unable or unwilling to provide adequately for the health and safety of the people it detains," said Clara Long, a senior US researcher at Human Rights Watch in a statement. "The Trump administration's efforts to drastically expand the already-bloated immigration detention system will only put more people at risk."

Read More