Authorities in Costa Rica investigating the death of former New York Yankees outfielder Brett Gardner’s teenage son have concluded that he died of carbon monoxide poisoning.
Miller Gardner, 14, was found dead on March 21 in his hotel room at the Arenas Del Mar resort in Manuel Antonio, Costa Rica, during a family vacation.
In a statement Wednesday, Randall Zúñiga, director of the Judicial Investigation Agency of Costa Rica, said toxicology tests for carbon monoxide showed a saturation level of 64% in Gardner's body. Concentrations above 50% of carboxyhemoglobin are considered lethal.
Additional tests for the presence of drugs such as fentanyl were negative.
Earlier this week, Costa Rican police said they discovered high levels of carbon monoxide while conducting tests in Miller Gardner's room at the resort.
A spokesperson for the resort told ABC News that the high levels of carbon monoxide were detected "in a mechanical room that guests do not occupy."
"The levels in the hotel room were non-existent and non-lethal," the hotel spokesperson said.
Costa Rican officials initially said that they suspected Miller Gardner died from possible "food intoxication," or food poisoning, and that they were working to determine if his death was caused by “possible asphyxiation” from a reaction to the food.
They later ruled out both as causes of his death.
‘An unimaginable loss’
Brett and Jessica Gardner announced their son's death in a statement posted by the Yankees to X on March 23, saying he died after "falling ill along with several other family members while on vacation."
"We have so many questions and so few answers at this point, but we do know that he passed away peacefully in his sleep on the morning of Friday, March 21," the statement read. "Miller was a beloved son and brother and we cannot yet comprehend our life without his infectious smile. He loved football, baseball, golf, hunting, fishing, his family and his friends. He lived life to the fullest every single day.”
Miller Gardner was Brett and Jessica Gardner’s younger son. They have another son, Hunter.
Brett Gardner spent his entire 14-season major-league career with the Yankees. The one-time All-Star and Gold Glove Award winner retired following the 2021 season.
"Words feel insignificant and insufficient in trying to describe such an unimaginable loss," the Yankees said in a separate statement posted to Facebook. "It wasn't just Brett who literally grew up in this organization for more than 17 years — so did his wife, Jessica, and their two boys, Hunter and Miller."
The Gardners expressed gratitude for the outpouring of support they’ve already received.
"We are so thankful to all who have reached out to offer support and encouragement during this difficult time and we are confident our faith, family, and friends will help us navigate this unimaginable loss," the Gardners wrote in the statement. "Our prayers go out to Miller's teammates and friends, as well as to all other families who have lost a child far too soon as we share their grief."