A Welsh coal "hurrier" in 1840.

In 19th-century Wales, children as young as five worked in coal mines as "hurriers," crawling through narrow tunnels pulling heavy carts of coal. These children worked twelve-hour shifts in complete darkness, chained to carts that weighed more than they did, crawling on hands and knees through passages barely two feet high. The work was essential to Britain's industrial revolution, which ran on coal, but it destroyed children's bodies—many developed spinal deformities, lung diseases, and died young. With no child labor protections, families had no choice but to send their children into the mines to earn the wages needed to survive.