Zipingpu dam threatens millions

The Zipingpu reservoir can hold a staggering 1.1 billion metric meters of water, but the dam wall was cracked after the earthquake. Dujiangyan, with a population of 600,000 would be devastated by a dam failure first. Within a couple hours, water would then hit the provincial capital, Chengdu.

“Dujiangyan would be hit first,” says Environmental sciences professor Ai Nanshan. “You can imagine water levels as high as two-story buildings within 10 minutes.