The Wayne County Medical Examiner's Office released the official cause of death of two children who died while sleeping in a van with family in Detroit.

DETROIT, MI – The Wayne County Medical Examiner’s Office determined the two children found not breathing in a minivan outside Detroit’s Greektown Casino died of carbon monoxide poisoning, Fox 2 Detroit reports. Police originally thought the two children, Darnell Currie Jr., 9, and A’millah Currie, 2, froze to death on Feb. 10.

On Feb. 10, the children's family was parked at the Hollywood Casino at Greektown when their car stopped running in the middle of the night, officials have previously said. Darnell Currie Jr. and A'millah Currie later stopped breathing and died.

Two Detroit children who recently died in a van in below-freezing temperatures were victims of carbon monoxide, not exposure to cold weather, authorities said Wednesday.

Feb. 10, Tateona Williams and her family, who were experiencing homelessness, were inside their van at Detroit's Greektown Casino. Inside were her five children. Williams first discovered one of her kids was not breathing that morning.

Authorities in New Mexico continue to investigate the cause of death of actor Gene Hackman and his wife​ Betsy Arakawa, but they say it does not appear to be carbon monoxide poisoning.