Hsing-Hsing the giant panda died at the National Zoo today here in Washington. He was 28. The panda came to the U.S. as a formal gift from the people of China, following President Nixon's trip there in 1972. With his mate Ling-Ling, the panda was one of Washington's most popular attractions, greeting some three million visitors a year. Failing in recent years, he was treated by zoo keepers for cancer and kidney disease, with medicine hidden in his favorite snack, blueberry muffins from Starbucks. Jacki visits the National Zoo today to remember one of the most visible symbols of Sino-American diplomacy.