March 11, 2026, 4:29 p.m. ETThe death of an ICE detainee who was found unresponsive in his cell at the Miami Correctional Facility last month has been deemed natural.Miami County Coroner John Boyer said Lorth Sim died of atherosclerotic cardiovascular disease, which involves the hardening of arteries due to plaque buildup. Boyer said diabetes is a contributing cause.The 59-year-old Cambodian national was pronounced dead at 7:10 a.m. on Feb. 16, when staff found him unresponsive in his cell at the state prison, according to a news release from ICE. The agency said Sim died despite lifesaving efforts from prison staff and emergency responders. Sim's death is the first at the maximum security prison since it began housing detainees for the U.S. Immigration & Customs Enforcement.Democratic lawmakers from Indiana have called for transparency from the Trump administration, which has nicknamed the prison the "Speedway Slammer," despite misgivings from the owner of the Indianapolis Motor Speedway.State Rep. Ed DeLaney, D-Indianapolis, has called for a thorough assessment of the medical care Sim was receiving.Sim was prescribed metformin, which is used to treat high blood sugar, Boyer said, adding that officials are still waiting for lab test results to determine whether Sim was taking the oral medication at the time of his death. Boyer said Sim had just died when prison staff found him.Sim entered the U.S. as a refugee in 1983 and became a lawful permanent resident three years later, according to ICE. He lost his legal status following criminal convictions. He was arrested for disorderly conduct in 1989, indecent exposure in 1996 and larceny in 2005. Immigration officers took him in custody in 2006, and he was ordered to be deported to Cambodia.He was arrested again by ICE officers on Dec. 30, 2025 and had been in ICE custody since. He was detained in Boston and was later transferred to the Indiana prison.Contact IndyStar reporter Kristine Phillips at (317) 444-3026 or at kphillips@indystar.com.