Unfortunately, because of the lack of child labor laws, children's working conditions were exactly like adults', that is to say unsafe, unsanitary, and generally unpleasant. The Industrial Revolution, often associated with the era of Queen Victoria in both England the her former colonies, represented a time of wildly escalating social and economic change, as people moved from the country in many places into the cities to work for cash in the new factory industry.
A factory worker's day, child or adult, normally began at 5 or 6 in the morning, and might go on until 5 or 6 in the evening six days a week. Because there were no guidelines or laws governing factory safety, horrific accidents, even deaths were common, and workers had no recourse in such cases, so disability or life insurance to fall back on. Additionally, health concerns were not addressed; many textile workers, including children, suffered lung ailments related to prolonged breathing of cotton fibers in the air where work was done. Children working in glass factories, which became common during the onset of the 1900's, suffered even more health problems related to the glass fibers in the air, including eye and lung problems, severe burns, and even heat exhaustion resulting from the factory's extreme temperatures.
Because the Industrial Revolution more or less began in England, the plight of child workers began there as well, where children as young as pre-school age were employed in not only in factories, but also in mines and even as chimney sweeps. Charles Dickens is famous for his novels such as Oliver Twist, which made pointed statements about the problems of the child labor system in England; Dickens knew of what he spoke, of course, having gone to work in a blacking factory at age twelve to assist his family after his father, a profligate spender, went to debtor's prison.
If an adult suffered health problems or a family suffered the death of its prime wage earner, and had no recourse, one can understand why a child would have none either, and in fact, a child's life was considered even less valuable. A family whose child had gone to work to help the family could likely be replaced with another sibling; this isn't to minimize the impact such a death might have on a family emotionally, but to suggest that child labor was not in the least questioned as an acceptable practice in Victorian England (and later, the United States).