Former New York Yankees outfielder Brett Gardner and his wife announced Sunday that their 14-year-old son, Miller, has died.

They released a statement that said in part:

“With heavy hearts we are saddened to announce the passing of our youngest son, Miller. He was 14 years old and has left us far too soon after falling ill along with several other family members while on vacation. We have so many questions and so few answers at this point, but we do know that he passed away peacefully in his sleep on the morning of Friday, March 21st.”

The Yankees also released a statement, calling the organization’s love for the Gardner family “unconditional and absolute.”

“Words feel insignificant and insufficient in trying to describe such an unimaginable loss. It wasn’t just Brett who literally grew up in this organization for more than 17 years — so did his wife, Jessica, and their two boys, Hunter and Miller.”

It was not immediately clear what illness befell upon Miller and other family members.