Miller Gardner, the 14-year-old son of former New York Yankees outfielder Brett Gardner, died from lethal exposure to carbon monoxide fumes while vacationing with his family in Costa Rica, authorities confirmed Wednesday. The Judicial Investigation Organization (OIJ) concluded a two-week probe, pinpointing the silent killer as the cause of the teenager’s tragic death on March 21 at the Arenas Del Mar Beachfront & Rainforest Resort.
Randall Zúñiga, director of the OIJ, detailed the toxicology findings from Miller’s autopsy during a press statement. “In the carboxyhemoglobin test, a saturation of 64% was found,” Zúñiga said. “This supports the police hypothesis that the death was due to exposure to poisonous gases such as carbon monoxide.” Carboxyhemoglobin forms when carbon monoxide binds to hemoglobin in the blood, and levels above 50% are considered lethal, according to medical standards. Zúñiga noted that Miller’s organs bore a distinct “layer”—a visible sign of carbon monoxide poisoning—further corroborating the results.
The Gardner family’s ordeal began on March 21 when Miller was found unresponsive in their hotel room in Manuel Antonio, a popular beach destination near Quepos. Initial theories suggested asphyxia or an allergic reaction, as the entire family—Brett, his wife Jessica, and their older son Hunter—reported severe symptoms requiring medical attention. However, an autopsy quickly ruled out choking or food-related causes, shifting the investigation’s focus.
A week later, on March 28, OIJ investigators, aided by a specialized hazardous atmospheres team, tested the hotel room and detected “high levels of carbon monoxide contamination,” Zúñiga explained in a March 31 press conference. Preliminary findings pointed to a machine room adjacent to the Gardners’ suite as the likely source, with contamination levels reaching up to 600 parts per million (ppm)—far exceeding safe limits, which should be zero in occupied spaces. “It’s believed there may have been some type of contamination from this dedicated machine room toward these rooms,” Zúñiga said, emphasizing the ongoing coordination with the U.S. FBI.
The toxicology report, finalized on April 2, ruled out other possibilities. “We tested for drugs, such as fentanyl and other substances, and all results came back negative,” Zúñiga confirmed. With no evidence of narcotics or other toxins, carbon monoxide emerged as the definitive cause. The OIJ plans to close the case, forwarding the report to Costa Rica’s Forensic Medicine department for final documentation by the autopsy expert.
The Arenas Del Mar Beachfront & Rainforest Resort, where the family stayed, initially disputed the OIJ’s findings. On April 1, hotel spokesperson Dana Cohen told the New York Post, “The levels in the hotel room were non-existent and non-lethal. There was an error in this initial report.” The resort claimed high carbon monoxide levels were confined to the mechanical room, not guest areas, and expressed heartbreak over the “tragic loss” while awaiting conclusive results. However, the OIJ’s subsequent toxicology evidence contradicted this, reigniting questions about the resort’s safety protocols.
Miller’s death has stunned the baseball community and beyond. Brett Gardner, a 14-season Yankees veteran known for his speed and tenacity, retired in 2021 after a career that included a 2009 World Series title. The Yankees honored Miller with a moment of silence before their Opening Day game against the Milwaukee Brewers on March 28, remembering him as a vibrant teen who “loved football, baseball, golf, hunting, fishing, his family, and his friends.”
The incident underscores the dangers of carbon monoxide, an odorless, colorless gas produced by fuel-burning devices like generators or heaters. According to the U.S. Consumer Product Safety Commission, non-fire-related carbon monoxide deaths have risen in recent years, with over 150 fatalities annually in the U.S. alone. Experts note that portable detectors—small, affordable devices—could prevent such tragedies, prompting calls for travelers to carry them, especially in unfamiliar accommodations like hotels or Airbnbs.
For the Gardners, the loss is profound. Miller, the younger of their two sons, was a two-sport athlete whose spark and warmth left an indelible mark. As the investigation wraps up, the focus shifts to accountability. The OIJ’s findings suggest a preventable failure, potentially tied to the resort’s maintenance of its mechanical systems. While Arenas Del Mar has not commented further since the toxicology confirmation, the case may spur legal or regulatory scrutiny.
This tragedy also highlights the importance of awareness. Carbon monoxide poisoning symptoms—headaches, nausea, dizziness—mimic common ailments, delaying detection without proper equipment. For families like the Gardners, who sought a relaxing Costa Rican getaway, the outcome was unthinkable. As Zúñiga concluded, “This was a strictly scientific effort that allowed us to find the real truth of the facts,” offering closure, if not comfort, to a grieving family.
