Miller Gardner’s Cause of Death Confirmed as Carbon Monoxide Poisoning

Costa Rican authorities identify a machine room near the hotel room as the likely source of contamination, while the Gardner family mourns their loss.

Costa Rican officials confirmed that Miller Gardner, son of ex-Yankees player Brett Gardner, died from carbon monoxide poisoning during a family vacation on March 21, 2025.
Toxicology results revealed a lethal carboxyhemoglobin saturation level of 64% in Miller’s blood, far exceeding the 50% threshold considered fatal.
Investigators traced the source of the carbon monoxide to a machine room adjacent to the family’s hotel room at the Arenas Del Mar hotel in Manuel Antonio.
Initial theories of asphyxiation and food poisoning were ruled out after an autopsy and further testing, clarifying the cause of death.
The Gardner family has requested privacy as they grieve, while the incident has raised broader concerns about carbon monoxide safety in hotels and travel accommodations.