The palace was moderately damaged during the Tibetan uprising against the Chinese in 1959, when Chinese shells were launched into the palace's windows. Before Chamdo Jampa Kalden was shot and taken prisoner by soldiers of the People's Liberation Army, he witnessed "Chinese cannon shells began landing on Norbulingka past midnight on 19 March 1959... The sky lit up as the Chinese shells hit the Chakpori Medical College and the Potala." It also escaped damage during the Cultural Revolution in 1966 through the personal intervention of Zhou Enlai, who was then the Premier of the People's Republic of China. Tibetan activist Tsering Woeser claims that the palace, which harboured "over 100,000 volumes of scriptures and historical documents" and "many store rooms for housing precious objects, handicrafts, paintings, wall hangings, statues, and ancient armour", "was almost robbed empty". On the other hand, tibetologist Amy Heller writes that "the invaluable library and artistic treasures accumulated over the centuries in the Potala have been preserved."