Modern coal mining and railroading are much safer than it was in the Gilded Age. While I don't condone the actions of the robber barons, it seems like there was no liability back then if someone got hurt. If anyone has a workplace injury nowadays, its the employer's responsibility to pay. Entrepreneur's have incentives to prevent work place accidents and keep their employees healthy for health-insurance reasons.
In addition, as the wealth of society grows, employees can ask for different kinds of compensation for their work, for instance, health-insurance or better work conditions. Most coal miners today make good money. Its not a profession for just the dirt poor anymore. I also don't agree that health-insurance should be mandated for employers to supply. However, employees should be able to chose if they want health insurance or prefer to be compensated in wages.
Furthermore, capitalism has nothing to say about moral issues, however, the legal and justice system is the proper place to determine the moral obligations that employer's have to employees, while that could be anything from health, treatment and safety.
Lastly, capitalism is not a complete system. Its only most effective and prosperous when its regulated by a good justice system. If these conditions are met, entrepreneur's have incentives to treat their employees' properly. Moral problems would exist under communism and socialism, however, these systems are just as unequipped to deal with them. The justice systems' in socialism and communism seem that they would be far less impartial too.
Response to Malaysia problem
While I don't think we should punish companies for moving into foreign countries, the United States ought to ban products from foreign companies that were made under highly immoral circumstances. For instance, companies that pay immoral bribes to officials to avoid their responsibilities or prevent their criminal prosecution.