Carbon monoxide poisoning may be cause of death of former Yankees outfielder Brett Gardner’s son, officials now say
(Gray News) - The youngest son of former New York Yankees outfielder Brett Gardner and his wife, Jessica, has died after falling ill during a family vacation to Costa Rica.
Miller Gardner was 14.
Miller Gardner died suddenly in his sleep the morning of March 21, according to a statement from the couple that the Yankees released online.
CNN reports that officials believe the teen’s death is related to carbon monoxide inhalation, according to the Judicial Investigation Agency (OIJ) of the Central American country.
OIJ director Randall Zúñiga explained Monday during a press conference that the teen was staying in a room at the Arenas Del Mar resort that was next to a machine room for the hotel.
According to CNN, the official said the room “is believed to have some type of contamination that could have caused this situation.”
While officials are waiting for the final result of the toxicology reports to confirm the exact cause of death for Miller, CNN says a report made to the Ministry of Health indicates contamination levels were found of up to 600 parts per million, where they should be at zero.

Authorities had initially cited food poisoning-related asphyxiation as the teen’s cause of death but quickly ruled that out as the reason.
Brett Gardner, 41, played baseball at the College of Charleston from 2002-2005 when he was drafted by the Yankees.
He’d play his entire 17-year professional career with the Yankees organization. The speedy outfielder batted .256 with 139 homers, 578 RBIs, 274 steals and 73 triples in 14 seasons from 2008-2021.
He retired after the 2021 season and was inducted into the Charleston Baseball Hall of Fame in 2023.
The Yankees said the organization was “filled with grief.”
“Words feel insignificant and insufficient in trying to describe such an unimaginable loss,” the team said in its 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.”
Copyright 2025 Gray Local Media, Inc. All rights reserved.