Brett Gardner finally has a disheartening yet long-awaited update on his 14-year-old son Miller’s death.
The Costa Rican authorities have announced that Miller may have died from carbon monoxide poisoning while on vacation with his family.
The tragic incident occurred on March 21, 2025, at the Arenas Del Mar Beachfront & Rainforest Resort in Manuel Antonio, Costa Rica. Miller was staying with several family members.
The Costa Rican Judicial Investigative Agency led investigation revealed high levels of carbon monoxide contamination in the family’s hotel room. The OIJ’s director, Randall Zuniga, emphasized that the room was located adjacent to a specialized mechanical room. And the same room could have been a source of the hazardous gas contamination.
Zuniga stated in a press conference that tests detected carbon monoxide levels reaching as high as 600 parts per million. The significantly dangerous level given that the safe level should be zero.
Gardner’s young son Miller’s sudden death has perplexed both medical professionals and investigators. Initially, early reports speculated he may have died from food poisoning or asphyxiation during his sleep.
However, those theories have been dismissed as further evidence emerged connecting his death to carbon monoxide exposure.
First Responding Doctors Spent 30 Minutes To Revive Brett Gardner’s Son Miller

The investigation, which is a joint effort between Costa Rican authorities and the FBI, remains ongoing as officials await the completion of toxicology reports to confirm the exact cause of death. Zuniga pointed out that the contamination likely caused the health issues experienced by Miller and other family members prior to the incident.
The Gardner family was reportedly enjoying their vacation when Miller and several relatives fell ill, with Miller ultimately found unresponsive. Doctors on-site spent approximately 30 minutes attempting to revive him.
In the wake of the tragic circumstances surrounding Brett Gardner’s son’s death, the hotel where the Gardner family was staying expressed its condolences and commitment to cooperate with the ongoing investigation. The resort has sought to reassure guests about their safety amid growing concerns.
Miller Gardner’s shocking passing has cast a shadow over the tourism industry in Costa Rica. Recent reports indicate that vacation cancellations have surged as travelers become wary of potential safety issues.
This incident comes after another case where three American tourists in Belize were found dead from carbon monoxide poisoning in their hotel room.