Carbon monoxide killed son of former Yankees star Brett Gardner, autopsy finds

• Miller Gardner was on holiday with family in Costa Rica
• Fumes may have leaked from adjacent engine room

Carbon monoxide poisoning was the cause of death of the teenage son of former New York Yankees outfielder Brett Gardner, authorities in Costa Rica said on Wednesday night.

Randall Zuniga, director of the Judicial Investigation Agency, said 14-year-old Miller Gardner was tested for carboxyhemoglobin, a compound generated when carbon monoxide binds to hemoglobin in the blood. When carboxyhemoglobin saturation exceeds 50%, it is considered lethal. In Gardner's case, the test showed a saturation of 64%.