Free market pressures exposed the U.S. steel industry's own internal problems, which included a now-outdated manufacturing base that had been over-expanded in the 1950s and 1960s, hostile management and labor relationships, the inflexibility of United Steelworkers regarding wage cuts and work-rule reforms, oligarchic management styles, and poor strategic planning by both unions and management. In particular, Pittsburgh faced its own challenges. Local coke and iron ore deposits were depleted, raising material costs. The large mills in the Pittsburgh region also faced competition from newer, more profitable "mini-mills" and non-union mills with lower labor costs.