Unit 70 "Tsunami Generation" Braves Physical, Psychological Scars Although many people call tsunamis "tidal waves", they are not related to tides but are rather a series of waves, or "wave trains", usually caused by earthquakes. Tsunamis have also been caused by the eruption of some coastal and island volcanoes, submarine landslides, and oceanic impacts of large meteorites. Tsunami waves can become more than 30 feet high as they come into shore and can rush miles inland across low-lying areas. From Thailand to Somalia, more than 170,000 people died in the tsunamis. The United Nation's Children Fund (UNICEF) first estimated children made up one-third of the death toll. But that percentage, if anything, might be too low. In many hard-hit countries, birth rates tend to be high and life expectancies low -- 30 to 43 percent of residents are age 18 or below -- so children fatality rates somewhat mirror the population breakdown. Beyond that, children are generally more vulnerable than adults -- smaller, weaker and more susceptible to nature's fury and disease. Children are much less able to run away, fight the water, hold onto or climb a tree. Yet, amid the tragedy, remarkable events left room for hope and faith. Off Thailand's Khao Lak tourist resort, a woman discovered an 18-month-old boy from Kazakhstan floating on a mattress. His parents are thought to have perished. Twenty-day-old Suppiah Tulasi also survived. Her parents found her lying on a mattress in 5 feet of water hours after waves flushed them from a restaurant. Seattle, Washington, residents Ron Rubin and Rebecca Beddall climbed to the roof of their hotel in Phuket, Thailand, where they spotted 18-month-old Hannes Bergstrom. They took the Swedish boy -- rescued reportedly with the help of a Thai princess -- to a local hospital. Hannes eventually rejoined his father and other relatives. His mother remains missing. Now sleeping 40 to room, the children are both supremely unfortunate and fortunate. They extreme challenges -- physical, psychological and otherwise -- in the coming months. But they are alive, having survived a disaster that took thousands of lives including, in many case, their parents, siblings and friends. According to WebMD, half the children exposed to the catastrophe may suffer from post-traumatic stress disorder, a rate about 20 percent higher than adults. "I used to play near the waves all the time back home, but I don't want to see it now," Chiranjivi, 12, told The Associated Press, "I can't forget that day." Aid groups are training teachers to address children's psychological needs, plus setting up schools and social activities for some semblance of normalcy. The priority is reuniting children, especially orphans, with relatives. UNICEF urges authorities to be on alert for people who may try to exploit abandoned children, particularly for human trafficking. Young victims' physical health also requires urgent and sustained attention. Cramped refugee camps, lack of food or clean water and poor sanitation foster prime conditions for measles, cholera and diarrhea outbreaks, as well as dehydration and malnourishment. Efforts are under way to prevent such problems, helping children to cope with their trauma and restoring a protective and supportive environment.