♪ ♪ >> migrant workers have played a vital role in china's rapid economic growth. more and more people from rural parts now work in the cities. they have come in search of wealth, but many leave their

children behind at home with their aging grandparents or in some cases alone. this june, four such young siblings committed suicides by consuming pesticides, believed to be caused by loneliness and im positivishment, the tragic news shocked the nation. roughly 61 million minors reportedly live apart from one or both of their parents in china today. half of that figure live without either of their parents at home. such children become especially unstable during the summer school break when their sense of isolation is at its most desperate.

one elderly volunteer checks on children left behind. he's devoted to ensuring their emotional well being, making sure they receive proper schooling. at the root of the problem is the economic gap between people in urban and rural areas. another factor is the focus on materialism and obtaining wealth. we follow the growing concerns in china for the children left at home to fend for themselves.

jiefang, sichuan province, quiet and nestled among hills. radish farming is the primary source of income. these days, however, surviving on farming alone is difficult so almost half of the residents have left to work in metropolitan areas. only the elderly and children remain. at present, while their parents are away, 74 children in the village with their grandparents. one man has been watching over these youngsters more than ten years. 67-year-old shuchu tsi makes frequent visits to the children's home, particularly in july and august when they are off school for their summer break.

♪ visiting each child under the scorching sun is hard work for him, especially as the homes are so far apart. he heads to the house of an elementary school second grader.

won jao chin lives with his grandparents. his parents left the village soon after he was born and only come home once a year. his grandfather is a big breeder and works all day from sun up to sun down. he says he wants the best life possible for his grandson. chow chin is an old child. he often spends the summers playing alone in his room. his parents and grandparents have showered him with toys and games to try and distract him from his loneliness.

on this day, chow chin is on his way to his friend's house. he can't wait to show them the latest toy his father sent him. he also much prefers playing with his friends than by himself.

chaoquin's friends are 12 and 10-year-old as i understand siblings. their parents also work in the city. he quickly assembles the toy. it's something he's become used to. his friends are fascinated by their toy. chaoquin is surprised to see that his friend's mother has returned today. she's decided to stay to take care of her children and aging parents while her husband continues working away. watching his friends with their mother, chaoquin's mood suddenly

changes. only seconds ago, they were all happily checking out his new toy. but now, without so much as a good-bye, chaoquin is on his way home. chaoquin has been living with his grandparents ever since he could remember. materially, he wants for nothing. but he only gets to see his parents once a year, usually

over the chinese new year holiday. it was five years ago when he received his first gift from his father, a simple stone from a riverbed. chaoqian says it's his treasurer and he cherishes it dearly.

>> many of the children left at home feel an extreme loneliness and are emotionally unstable, even if they don't seem so at first. aside from empathy, however, there is another reason for his concern for these children. many of their parents are students. when he was a teacher at the village elementary school. the next visit is a home across

the river. an elderly couple greet him. they live with their 9-year-old granddaughter. he parents work in a coastal city around 9,100 kilometers away. they were able to build a new house last year for a cost of $50,000 u.s., equivalent to a lifetime of savings for local

the grandparents are very proud of the new home. the home has much more space than the whole family could ever wish to use. it may seem than wei's parents are already wealthy enough, but they have no plans to return anytime soon.

once a week, huiping's parents call home. for the past few years, huiping has been refusing to speak to her parents.

>> huiping's mother hasn't been home for four years. her father for two years. the separation has been taking a heavy toll on their relationship with their daughter.

>> huiping's room is across from the living room. for long periods, there is often no one around to watch her and make sure she's behaving. during the summer months, her grandparents spend a lot of time away from the house. they work the fields, as it's rice harvesting season. they tend to a 6,000 square meter rice patti with most working age adults in the city. the elderly are left to farm the fields themselves.

with her grandparents so occupied, huiping often spends many long hours along in the big house. recently, though, she's been spending time talking with a special companion. her favorite doll.

when she's alone, she never let's go of her. she's become the most dependable and comforting member of the family.

>> shu believes parents should give priority to being with their children, even if it means reducing their income. his suggestions aren't taken seriously. he visited five homes today.

he says he sometimes feels helpless as the children's emotional suffering isn't really considered by the parents. sanjian is a neighboring town to jiafeng. at 8:00 a.m. every weekend, children from all over the district make their way toward a building in town. called the center for left behind children, it's a place dedicated to youngsters whose parents are away.

shu began volunteering at the facility in 2006 after he retired from teaching. the center, funded by the local government and private sector donations, offers artwo worksho and classes to assist kids with school work. shu tries to ensure the children have as much fun as possible, especially during the summer when they don't have school to keep them occupied.

chaoqian gets straight into the assignment. his drawing shows his parents returning home with big smiles on their faces. shu says the pictures reveal the children's hiding feelings and emotions that are bottled up inside. huiping doesn't even know her mother's name and feels distant from her parents. even so, she puts her mother in her picture.

each drawing expresses the same thi thing: the children's desperate longing for love and attention. shu wants to show the drawings to the children's parents. he hopes that if they can understand how lonely their children really feel, they'll reconsider their work situation and come home more often.

on this day, shu has decided to get huiping out of the house. he's concerned about her being alone for so long. he takes her to his home. he wants to help her with her homework. he discovered that it's full of mistakes. her school grades haven't been good for some time.

shu fears that academic gaps will eventually lead to income gaps for the children he watches over. he knows that their grades will affect their futures, so he's doing what he can to ensure they keep up with their school work. meanwhile, shu's wife prepares

lunch. even though she complains, shu's wife has made various dishes. it's a special, nutritious treat for huiping. who usually eats instant noodles alone at home for lunch.

>> as huiping plays with shu's neighbor's kids, shu falls asleep from exhaustion. at 67 years old, his work is beginning to take its toll.

tens of millions of children like these pose a simple but serious question for the people of china. what is happiness?

♪[theme music] ♪[theme music] ♪[theme music] welcome to "potus 2016" where we call the presidential horse race and pour cold, hard facts on the overheated campaign rhetoric. today, as the prospect of donald trump winning or losing the presidency splits the republican party, we dig for the roots of the fracture and consider the consequences. to begin, for hillary clinton, another unlucky derby.