A new toxicology report found the 14-year-old South Carolina boy's body had carboxyhemoglobin level of 64%, which is 14% above what is considered lethal.

Miller Gardner -- the 14-year-old son of former New York Yankees outfielder Brett Gardner -- died from carbon monoxide poisoning, Costa Rican authorities have said.

Miller Gardner, the 14-year-old son of former New York Yankees outfielder Brett Gardner, is believed to have died as a result of carbon monoxide poisoning.