Colleagues, alumni, students, family and friends of sociology instructor Greg Olsen gather to celebrate his life and his contributions to the University at a tree planting ceremony held Thursday, Nov. 29, at the northwest corner of Swart Hall. The ceremony was followed by a reception at Pollock Alumni House. Olsen was an adviser to the Sigma Pi fraternity, a member of the Senate of Academic Staff, and a founding member of the Earth Charter. He passed away May 27.