Miller Gardner Cause of Death Revealed: Carbon Monoxide Poisoning Confirmed in Tragic Vacation Incident
Summerville, South Carolina, April 3, 2025 – The official cause of death for Miller Gardner, the 14-year-old son of former New York Yankees star Brett Gardner, has been confirmed as carbon monoxide poisoning, nearly two weeks after his sudden passing on March 21 during a family vacation in Costa Rica. Costa Rican authorities released the toxicology results late Wednesday, April 2, ending weeks of speculation and delivering a somber answer to a grieving family and community.
A Lethal Exposure
Randall Zúñiga, General Director of Costa Rica’s Judicial Investigative Agency (OIJ), announced the findings in a press statement, detailing that Miller’s carboxyhemoglobin level—a measure of carbon monoxide in the blood—reached 64%, well above the lethal threshold of 50%. “This saturation level is clearly fatal,” Zúñiga said, noting a “layer” on Miller’s organs during the autopsy further confirmed exposure to the odorless, deadly gas. The investigation pinpointed “high levels of carbon monoxide contamination” in the family’s hotel room at the Arenas Del Mar Beachfront & Rainforest Resort in Manuel Antonio, with readings up to 600 parts per million—far exceeding safe limits.
The source? A “specialized machine room” adjacent to the Gardners’ suite, where authorities suspect a malfunction or leak released the gas overnight. “It’s believed this contamination reached the guest rooms, causing the incident,” Zúñiga explained, adding that the OIJ, in coordination with the FBI, continues to probe the resort’s infrastructure. The hotel, which passed a health inspection on March 14, had claimed Monday that carbon monoxide levels were “non-existent and non-lethal,” a stance now contradicted by forensic evidence.
A Family’s Nightmare
Miller’s death followed a harrowing night. On March 20, Brett Gardner, 41, his wife Jessica, and their sons Hunter and Miller fell violently ill—suffering severe stomach cramps, vomiting, and diarrhea—after dining at Le Papillon, a restaurant at nearby Hotel La Mariposa. A resort doctor treated them with medication, and all retired to their rooms. The next morning, Miller was found unresponsive in his bed, having passed peacefully in his sleep. Initial theories of food poisoning or asphyxiation were ruled out last week, shifting focus to an environmental cause.
“Brett and Jessica thought it was just a bad meal,” a family friend told Us Weekly. “They had no idea something in the room could kill him.” The Gardner family’s statement on March 23, shared via the Yankees, expressed their anguish: “We have so many questions and so few answers… He was 14 and has left us far too soon.” Posts on X reflect the shock, with one user writing, “Carbon monoxide at a resort? That’s terrifying—how does this happen?”
A Resort Under Scrutiny
The Arenas Del Mar, a luxury eco-resort 50 miles south of San José, now faces intense scrutiny. While it cooperated with the OIJ and insisted its staff didn’t administer medication beyond a licensed doctor’s care, the confirmed contamination has sparked calls for accountability. “We are heartbroken,” the resort reiterated in a statement to PEOPLE, but declined further comment Wednesday, citing the ongoing judicial process. Local staff, including a bartender who spoke to the New York Post last week, voiced fears of legal repercussions, with the town of Manuel Antonio on edge.
The case echoes a recent Belize incident where three American women died of carbon monoxide poisoning in a hotel, highlighting the silent danger in tourist hotspots. Costa Rica’s Ministry of Health and Fire Department have been notified to address the resort’s “confirmed contamination,” Zúñiga said, though no immediate closures have been ordered.
A Community Mourns
Miller, an honor roll student and junior varsity athlete at Pinewood Prep, was remembered in a gut-wrenching obituary as a vibrant teen who “lived life to the fullest every single day.” His love for baseball, football, and family mirrored his father’s grit—Brett, a 2009 World Series champ, spent 14 seasons with the Yankees. On Opening Day, March 27, teammate Aaron Judge honored Miller, saying he had the Gardners “on his mind.”
As Miller’s body is prepared for repatriation, delayed by Costa Rica’s forensic backlog from gang violence, the family leans on faith and support. Their plea for donations to Make-A-Wish reflects a legacy of hope amid loss. For now, a community—and a nation—reckons with a preventable tragedy, as the quest for answers gives way to a call for change at a resort where paradise turned deadly.
