Demolition of the last cofferdam protecting the just-completed main wall of the Three Gorges Dam, the world's largest, started at 4:00 on Tuesday afternoon in the middle reaches of the Yangtze River, China's longest waterway, with enough explosives being used to topple 400 10-story buildings.

The operation took just 12 seconds causing nearly 190,000 cubic meters of concrete fragments from the upper-30-meter section of the cofferdam to tumble into the river.

The removal of the cofferdam means the main wall of the Three Gorges Project will now properly begin its role in flood control two years ahead of the original schedule.

The Three Gorges Dam in central China's Hubei Province was completed on May 20. This was a hugely significant construction accomplishment which provides a water control project designed to tame the flood-prone Yangtze River.

(Xinhua News Agency June 6, 2006)