Why it's hard to assess the scale of disaster in Tibet

Laura BickerChina correspondent Tibet, which China annexed in the 1950s, is one of the most strictly controlled regions in the country. It has long demanded greater autonomy and is heavily monitored because Beijing fears any signs of instability such as protests. That is why orders have come personally from the top leader Xi Jinping and why Premier Li Qiang visited the site on Thursday. It is rare for him to make a visit so soon after a major disaster. To get into Tibet requires a special visa a