Ng Han Guan, Associated Press
A security guard takes a break Monday next to sandbags piled near the glass wall of a bank in the Sichuan town of Mianyang, China. It is being threatened by the quake-caused Tangjiashan lake, which could flood more than 1.3 million people downstream. The lake continued to swell Monday despite efforts to blow up boulders in a diversion channel built to speed drainage.

A security guard takes a break Monday next to sandbags piled near the glass wall of a bank in the Sichuan town of Mianyang, China. It is being threatened by the quake-caused Tangjiashan lake, which could flood more than 1.3 million people downstream. The lake continued to swell Monday despite efforts to blow up boulders in a diversion channel built to speed drainage.