(CNN) - A flaring furnace blasts another wave of searing heat on the faces of workers hauling bricks under a southern Indian sun.

They work up to 22 hours a day propping heavy stacks of bricks on their heads. None expects to be paid for this labor. None knows how long they'll be kept here. Some are as young as three years old.

Manoj Singh was one of 149 people rescued this year from a brick kiln outside Hyderabad, India. Like millions of other Indians, the toddler was born into extreme poverty.

When CNN correspondent Mallika Kapur visited Manoj's family, now back home, he and the some of the 34 other children freed, showed her how they would make the bricks from wet clay.

"They recall from their muscle memory," says Anu George Canjanathoppil, of International Justice Mission, a non-profit dedicated to eradicating slavery around the world. "So if you ask them to explain what they did, they cannot say."

Older laborers, however, had plenty to say. FULL POST