SAFETY HARBOR, Fla. (WFLA) — As investigators work to determine how 17-year-old Ángel Eduardo Maradiaga Espinoza died just days after arriving at a migrant shelter in Safety Harbor, new details have emerged surrounding the Honduran teenager’s final moments.

Pinellas County Sheriff’s Office confirmed the boy likely died in his sleep after suffering an epileptic seizure.

Espinoza’s mother, Norma Saraí Espinoza Maradiaga, told the Associated Press that he has had epilepsy since he was a child. Sheriff Bob Gualtieri said preliminary reports indicate the teenager was found with a cut on his tongue and likely had a seizure.

Maradiaga said her son’s seizures were “brief and not serious,” and he showed no apparent signs of being sick before leaving his hometown.

“He had epilepsy, but it wasn’t an illness that threatened him, because he had had it since he was eight,” she told the Associated Press. “The longest a seizure would last was less than a minute. It seemed like it only hit him a little.”

Espinoza died on May 10, just days after the U.S. Department of Health and Human Services placed him at the shelter in Safety Harbor, run by Gulf Coast Jewish Family and Children Services. He left home on April 25, hoping to reunite with his father in the U.S.

“Since he was 10 years old he wanted to live the American Dream to see his father and have a better life,” Maradiaga told the Associated Press. “His idea was to help me. He told me that when he was in the United States he was going to change my life.”