Carbon monoxide poisoning is reportedly what caused the death of Miller Gardner, the teenage son of retired New York Yankees outfielder Brett Gardner, officials say.Authorities in Costa Rica confirmed that 14-year-old Gardner ha d toxic levels of carboxyhemoglobin in his body, the Associated Press reported, citing Randall Ziga, director of Costa Rica's Judicial Investigation Agency. Gardner died on March 21 while on a family vacation to the country.Carboxyhemoglobin is the compound that results when carbon monoxide binds to hemoglobin in red blood cells, preventing oxygen from binding effectively. According to the AP, Gardner has 64% saturation of carboxyhemoglobin in his blood, while anything over 50% is considered lethal.IN OTHER NEWS | Kids died of carbon monoxide poisoning in Detroit parking garage incidentOfficials initially believed Gardner died from asphyxiation caused by possible "food intoxication." However, that cause of death was ruled out earlier this week after officials said "high emission of carbon monoxide" were detected in Miller's hotel room, which was reportedly located near a mechanical room.Investigators said that's what could have been the source of high levels of carbon monoxide in Miller's room. Then the head of the Costa Rican judicial police said that during the autopsy, a "layer" was found on the teen's organs, indicating a presence of poisonous gas, the AP reported.Parents Brett and Jessica Gardner announced last month that their son Miller "passed away peacefully in his sleep" on March 21st after falling ill during their vacation. "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 Gardner family said in a statement made public by the New York Yankees. "Our prayers go out to Miller's teammates and friends, as well as to all the other families who have lost a child far too soon as we share their grief. Please respect our wishes for privacy as we mourn and search for healing."The Yankees said the organization was "filled with grief" after learning about Gardner's passing."Words feel insignificant and insufficient in trying to describe such an unimaginable loss," the franchise said in a statement. "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.""Our love for the Gardner family is unconditional and absolute, and we will offer our enduring support while understanding their desire for privacy at this time," the Yankees organization added. "May Miller rest in peace."Brett Gardner, 41, spent his entire MLB career with the Yankees after being drafted by New York in 2005. Over the course of his career, the fleet-footed outfielder would go on to bat .256, with 139 home run, 578 runs batted in, and 274 stolen bases.Gardner also won one World Series with the team in 2009 before retiring after the 2021 season. ...read more read less