Thousands of soldiers combed remote mountains in China's Sichuan province Monday in search of a military helicopter that crashed while transporting earthquake victims. The Russian-designed Mi-171 transport had been carrying 19 people, 14 of them people injured in the quake, when it flew into fog and turbulence and crashed near the epicenter of the May 12 quake in the town of Wenchuan on Saturday, state media reported. The chopper was returning after dropping off four members of an epidemic prevention team in the town of Lixian, the official China Daily newspaper reported, underscoring efforts to prevent disease outbreaks in quake-hit areas and crowded camps for those made homeless. State broadcaster CCTV reported on its main noontime news broadcast that 4,000 soldiers were taking part in the search but gave no word on any survivors. China has relied heavily on its 250-strong fleet of Mi-171s to transport supplies and relief workers and evacuate the injured from widely scattered towns in the mountainous area where roads were wiped out by landslides. Meanwhile, soldiers completed work on a cannel to divert water from a lake formed when landslides triggered by the quake blocked the Tongkou river. Water levels in the lake had been rising steadily and threatened to flood surrounding areas, prompting authorities to evacuate nearly 200,000 people already uprooted by the quake. Downstream villages stood empty Monday after police and soldiers ordered people out, although some families were holding out for further confirmation. "We're waiting until the last moment," said farmer Liu Zhenyang, 35, sipping tea with his family in the town of Qinglian. "Then we'll run to the hills." As a warning, authorities had spray-painted a flood line outside their door just level with their toes. On top of nearby Taohuashan, or Peach Blossom Mountain, hundreds of families were waiting to see if their homes below would be swept away. People said the government would warn everyone with sirens and firecrackers if the lake burst. On the quake's three-week anniversary, a reconstruction committee has been set up under the National Development and Reform Committee, the Cabinet's top economic planning agency. An initial meeting resulted in a list of tasks and general schedule for completion, the NDRC said in a news release issued Monday. It gave no details and did not say when the meeting had been held. Committee members have dedicated themselves to a reconstruction plan that is "of high quality, that will stand the test of time, allow victims to rebuild their homesteads, and create a solid foundation and conditions for wider scale reconstruction," the NDRC news release said. The quake killed at least 69,000 and left more than 5 million homeless. Authorities have rushed to construct tent camps and prefabricated housing ahead of the summer rainy season and its expected hordes of disease-bearing mosquitoes. With local hospitals overwhelmed, more than 10,000 of the injured have been transferred from Sichuan to 340 hospitals in Beijing, Shanghai and more than a dozen provicnes, the Health Ministry said on its Web site. Elsewhere in the quake zone, Hossam Elsharkawi, head of support operations for the International Federation of Red Cross and Red Crescent societies, said his organization was preparing to bring in two large water purification units that will provide clean water to 15,000 people each. "The government is doing an excellent job in urban areas, but it's taking time in places like this because it is so dispersed," said Elsharkawi, speaking in the village of Jiulong village, just north of the provincial capital of Chengdu. Elsharkawi said the federation expected to be helping with relief work in Sichuan for three years and would ship in 100,000 tents by the end of June. While describing the scale of the disaster as "massive," Elsharkawi praised the government's rapidly moving recovery effort and mobilization of aid. "They can teach the world a thing or two on responding to such large-scale disasters," he said.