Beneath a busy overpass in India’s financial capital Mumbai, a row of pastel-colored shipping containers houses an unlikely school serving some of the city’s most marginalized children.

Despite laws guaranteeing free schooling for children age 6 to 14, poverty and migration continue to keep many out of classrooms, particularly in sprawling cities like Mumbai, where many families survive through low-paying informal work.

Crippling urban poverty also means young children selling knick-knacks on streets are still a fairly common sight at crowded traffic intersections in big Indian cities.