As the death toll from China's deadliest earthquake in decades climbed to nearly 15,000, officials warned of potential calamities from broken rivers and dams strained to bursting point. State media said around 2,000 soldiers had been sent to repair "extremely dangerous" cracks in the Zipingpu Dam, up the river from the earthquake-hit city of Dujiangyan. On Thursday (May 15) morning, the dam could be seen releasing huge gushes of water as military and medical personnel set up rescue and relief areas near it. China ordered fresh waves of helicopters and aid to earthquake-devastated areas as the sheer magnitude of caring for tens of thousands of homeless survivors threatened to overwhelm relief efforts. The Communist Party leadership told officials to "ensure social stability" as Monday's (May 12) 7.9 magnitude quake in south-western Sichuan province spawned rumours of chemical spills, fears that dams could burst and scenes of collective grief. The official death toll estimate from Monday's quake stood at 14,866 as officials warned of uncertain risks from numerous dams that were damaged in the quake zone. In a speech that was posted on the Water Resources Ministry Web site (www.mwr.gov.cn ) on Thursday, Chen Lei, the Minister said "especially in Sichuan province, there are many dams, damage from the quake is extensive and the hazards are unclear." At the dam, workers could be seen using ropes to check for damages and cracks on the dam walls. Tens of kilometres away from the dam, the military has set up a base to use speedboats to enter areas near the earthquake epicentre of Wenchuan. Speedboats could be seen ferrying medical workers away and receiving injured victims to shore. Military personnel and medical workers turned the side of the dam into a temporary medical point as they took those with the most severe injuries into ambulances to be sent to hospitals in the provincial capital of Chengdu. Medical staff at the site described the situation in the worst-hit quake areas as "very severe". "Overall, we have sent three medical teams to Wenchuan. We are here to use this place as a backup medical post. We are here to treat those injured victims that will be evacuated here," said nurse Ou Zujun (o-zoo-jean), part of a team of medical staff from the Shenzhen People's Hospital. "According to some accounts from earthquake victims that were evacuated from Yingxiu, the situation is very severe. A lot of buildings there have collapsed and a lot of people were buried in rubble. Our colleagues have started operations and set up a medical point in Yingxiu," she added. A handful of earthquake victims arrived at the site by walking for more than five hours through cracked roads and trekking up mountainous areas. Medical staff attended to them immediately by giving them food and water before transferring them away in vehicles. They described the scenes of devastation in the quake-stricken areas. "The buildings back there have all collapsed. All of us climbed up to the top of the mountain because people say the water levels are rising there. We all ran up to the mountain top and a lot of old people have died and their bodies were just lying there," said Lin Fang, who trekked out of the disaster zone carrying her two-year-old baby on her back. "The roads there have all cracked up and the cracks can be seen as deep as three or four metres high. Also, some of the roads have sunk down. We could even see dead people inside their cars on the roads," said another earthquake victim, Guo Baizhong (pron: goore- bye-zhong). The ruling Chinese Communist Party's Standing Committee met late on Wednesday (May 14) to assess the calamity that has thrown a shadow over preparations for the Beijing Olympics in August. State media said the government ordered fresh waves of troops to be dispatched, raising the total to some 130,000 committed to the effort, and 100 more helicopters to help send rescuers and supplies to areas blocked by buckled roads. But the waves of rescuers appear to be hampered by lack of specialised equipment. Premier Wen Jiabao, a geologist himself, has made emotional appeals from the disaster zone urging on workers and comforting orphaned children and was set to travel on Thursday to Qingchuan. The quake was the worst to hit China since 1976 when up to 300,000 died.