Veteran comedian Bill Cosby returned to his alma mater in Philadelphia, Pennsylvania on Wednesday to mourn the loss of his former classmate, publishing mogul Louis Katz.

The billionaire businessman and philanthropist, who previously owned the New Jersey Devils ice hockey team and the Brooklyn Nets basketball team when it was known as the New Jersey Nets, was among seven people killed when the private plane they were travelling in crashed upon take-off in Massachusetts.

A special memorial was held at Temple University on Wednesday, when mourners included Cosby and former U.S. president Bill Clinton.