ROYAL OAK, Mich. -- The silverback gorilla at the Detroit Zoo has died.

Sunshine, 34, was being treated for a flu-like illness for the past week and his condition worsened on Tuesday.

“Sunshine was especially impressive because of his size. He was loved by Detroit Zoo staff, docents and visitors, and we all feel a tremendous sense of loss,” said Scott Carter, director of conservation and animal welfare.

Sunshine was a 550-pound western lowland gorilla and had been treated for heart disease for the past few years.

He had lived at the Detroit Zoo since 1996. He was on loan from the Columbus Zoo and was scheduled to return to Columbus with his companion, Toni, a 36-year-old female western lowland gorilla.

Toni will still return to Columbus.

Anyone wishing to make a contribution in Sunshine’s memory to fund either the national research effort on captive gorilla cardiac disease, or care of the Detroit Zoo’s Great Apes of Harambee, can send donations to: Detroit Zoological Society, 8450 W. 10 Mile Road, Royal Oak, MI 48067.