Watch: Why rescuers fear new barrier lake could cause another Nepal-Tibet flood

China has warned that there is simply a "high risk" that a barrier lake formed after a landslide along the Nepal‑Tibet borderline could breach its banks, triggering a second flood downstream. The warning follows Wednesday's deadly flash flood in the same region, which scientists say was caused when a mountain glacier collapsed into a river. China's Laura Bicker explains the situation. Read more: 'High risk' of water breaching and causing 2nd flood, warns China