The New York Yankees star’s 14-year-old son was found dead in his hotel room during the family’s vacation in Costa Rica.

Former Yankees player Brett and his wife, Jessica, announced last month that their teenage son, Miller, died on March 21. Here’s what we know about the cause of his death.

Costa Rica authorities confirmed that carbon monoxide poisoning was the cause of death of Miller Gardner, the 14-year-old son of former New York Yankees outfielder Brett Gardner.