A Mexican national who was being held by U.S. Immigration and Customs Enforcement in South Georgia died Tuesday from what the agency says may have been “self-inflicted strangulation,” becoming the eighth ICE detainee to die nationwide since October.

Efrain De La Rosa, 40, is also the fourth ICE detainee to die since May of last year after being held in federal immigration detention centers in Georgia. Like one of the others who died in Georgia, De La Rosa had been held in solitary confinement for many days before his death.

Authorities at Stewart Detention Center in Lumpkin found De La Rosa unresponsive in his cell at 10:38 p.m. Tuesday and immediately began to perform CPR on him, according to ICE. Stewart County emergency medical workers arrived at the detention center at 10:48 p.m. De La Rosa was pronounced dead at Southwest Georgia Regional Medical Center in Cuthbert at 11:29 p.m.

“The preliminary cause of death appears to be self-inflicted strangulation; however, the case is currently under investigation,” ICE said in a news release.

De La Rosa arrived in the United States 18 years ago, seeking a job, said his younger brother, Isai Romero, who lives in Raleigh, N.C. De La Rosa, who found work at a water filter company, suffered from bipolar disorder, a disease that can cause extreme mood swings, Romero said.

“I need to know exactly what happened,” Romero said of his brother’s death. “He was a good man.”

ICE took custody of De La Rosa on March 11 in Wake County, N.C., following his March 9 felony conviction for larceny. He was in deportation proceedings at the time of his death.

Before he died, De La Rosa had been isolated from the other detainees at Stewart for at least 10 days after making “inappropriate physical contact” with someone else in the detention center, according to ICE. CoreCivic, the Nashville-based company that operates Stewart Detention Center through agreements with ICE and Stewart County, declined to comment other than to confirm it is cooperating with officials investigating his death.

In May of last year, Jean Jimenez-Joseph, 27, a Panamanian national with a history of mental illness, hanged himself with a sheet in his solitary confinement cell at Stewart. He had been isolated for more than two weeks.

A day later, Atulkumar Babubhai Patel, 58, an Indian national who was being detained by ICE at the Atlanta City Detention Center, died at Grady Memorial Hospital because of complications from congestive heart failure. And in January, ICE detainee Yulio Castro Garrido, 33, a Cuban national, died from pneumonia after being held at Stewart.

RELATED: Brother: Cuban was healthy before dying of pneumonia in ICE custody

Stewart was the subject of a blistering federal investigative report published in December. Internal records from the U.S. Homeland Security Department Office of Inspector General’s report showed the sprawling immigration detention center has grappled with drug smuggling, chronic medical staff shortages and persistent safety problems that one employee called a “ticking bomb.”

Azadeh Shahshahani, the legal and advocacy director for Project South, an immigrant rights advocacy group, on Thursday repeated her organization’s call for the federal government to close Stewart.

“This horrific tragedy marks the third death at Stewart in less than 15 months. How many more people have to die before the government shuts down this horrendous place?” she said.

ICE said deaths in its custody are “exceedingly rare.” Twelve of its 324,000 detainees from fiscal year 2017 died.

“ICE is firmly committed to the health and welfare of all those in its custody,” the agency said in its news release, “and is undertaking a comprehensive agency-wide review of this incident, as it does in all such cases.”