Anthony York, the younger brother of 49ers chief executive office Jed York, has died at age 35.
The organization says Anthony York passed away Friday, but did not release a cause of death in their statement.
York was one of four children of 49ers owners John York and Denise DeBartolo York.
He is also survived by his twin sisters Jenna and Mara.
York was born in Youngstown, Ohio, where he went on to letter in football and baseball at Cardinal Mooney High School.
In adulthood, Tony York was an entrepreneur and a philanthropist.
"Tony's true passion lied in philanthropy, a trait instilled in him by his parents and shared closely with his brother and sisters," the family said in a statement.
He founded a company named Koda, which helps prepare young people for their first jobs when they graduate college.
His family says he was involved with several non-profit organizations, including the 49ers Foundation, and worked closely with incarcerated youth.
ESPN and the Associated Press contributed to this article.