Blood test revealed a carbon monoxide saturation level of 64% in Gardner’s system. Levels above 50% are typically fatal.

SAN JOSE, Costa Rica (AP) — Carbon monoxide poisoning was the cause of death of the teenage son of former New York Yankees outfielder Brett Gardner, authorities in Costa Rica confirmed Wednesday night.

The death of Miller Gardner, the 14-year-old son of former New York Yankees outfielder Brett Gardner, at a beach resort in Costa Rica is believed to be related to carbon monoxide inhalation, the Judicial Investigation Agency (OIJ) of the Central American country said Monday.