Miller Gardner, the youngest son of former New York Yankees outfielder Brett Gardner, died at the age of 14 while on vacation with his family.

A toxicology report after his death found high levels of carboxyhemoglobin, an indicator of carbon monoxide in the blood, according to a statement from Randall Zúñiga, the director of the Costa Rica Judicial Investigation Agency. Miller Gardner’s test showed a saturation of 64 percent, he said, adding that anything over 50 percent was lethal.

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.

Miller Gardner, the teenage son of former New York Yankees outfielder Brett Gardner, died of carbon monoxide poisoning, authorities in Costa Rica said Wednesday night.

Miller Gardner, the 14-year-old son of former Yankees outfielder Brett Gardner, dies last week while on vacation with his family in Costa Rica due to carbon monoxide poisoning, authorities confirmed Wednesday.

The family of former New York Yankees hero Brett Gardner released an obituary for their son, who died on a vacation to Costa Rica.

The statement refutes a Monday announcement by Costa Rican authorities that there were “high levels of carbon monoxide contamination” in the room where 14-year-old Miller Gardner was found

Brett Gardner's 14-year-old son, Miller Gardner, died from carbon monoxide poisoning during a family vacation in Costa Rica, as confirmed by officials. The toxicology report revealed a lethal level of carboxyhemoglobin in his body.

Brett Gardner's family was on vacation in Costa Rica when the former Yankee's son Miller, 14, fell ill and died unexpectedly on Sunday, March 23, PEOPLE can confirm.