Rajesh Sharma, a grocery story owner, has spent the last seven years teaching children under a bridge.
Nearly 200 underprivileged children from neighbouring ghettos now come to the school, which is known as "Free School, Under the Bridge" and is located in one of the world's most polluted cities, New Delhi.
There is no school bell, no seats, no tables. There is only one wall, which is concrete and part of the bridge itself. But there are blackboards. There are posters, and a teacher, and willing young students.
A speeding metro races over the bridge above the children's heads, but they continue their studies unperturbed.
Sharma, 45, dropped out of college with dreams of being an engineer but was held back because of financial constraints. Now he is fulfilling a different dream: educating underprivileged children.
"I was strolling by and saw children of labourers playing in the dust and mud when this metro bridge was under construction," Sharma told BuzzFeed News. "I spoke with the parents and asked, 'Why don't you send them to school?' They said, 'We want them to be educated but we can't afford their education and the school is too far.'"
With this thought in mind, Sharma started the open-air school under the same metro bridge. "I said, 'Okay, let me [teach starting] from tomorrow, I will take some time from my work and teach them.' I started with two or three kids [who had] nothing, no resources. The students used to sit on gunny bags."
Most of the children who attend the free school are born to migrant workers, labourers, rickshaw-pullers, farmers, and daily wage workers who live in shacks and ghettos in East Delhi.
A student named Pappu, 15, said with a big smile on his face "I love this school. I come here for studies and to draw." He walks 2km every day to reach the school.
The school is entirely dependent on public financial support, both from well-wishers and nongovernment organisations. People donate books, uniform, footwear, and food on a regular basis. The number of students has grown from around 50 students in 2010 to nearly 200 seven years later.
In 2011, Sharma was joined by Laxmi Chandra, a teacher from Bihar who now lives in Delhi, teaching science and mathematics to the students.
"Being a son of daily-wage labourers," Chandra, a science graduate from a university in Bihar, said, "I have seen the hardships of life since my childhood and I can tell you that education is the only thing which can change a man’s life.
"And when I see these kids, I remember my childhood days and I feel they must be educated."
The children also have a sports day on Saturdays where they play cricket, football, badminton, and other games under the bridge with donated sports equipment.
According to Unesco, as many as 124 million children and adolescents worldwide are out of school. Out of that that number, 17.7 million (14%) are Indian.