Dramatic mine accidents early in 2006 have led to passage of the first major amendment to federal mine safety law since 1977. The Mine Improvement and New Emergency Response Act requires each mine to have an emergency plan, increased supplies of oxygen, and improved rescue teams. Penalties for violations have also been increased. Although the bill had wide support in Congress, some Members have characterised it as only a "first step," to be followed by additional measures that would include a lower maximum limit on dust concentrations, underground refuges, communications and tracking devices, and greater emphasis on enforcement of standards. On January 2, 2006, the nation was reminded of the dangers of underground mining, as 12 miners died in an explosion and fire in the Sago mine in West Virginia. Subsequently, the Mine Safety and Health Administration (MSHA) issued new regulations; Congress has passed the first major revision of the mine safety law since 1977 and has taken further bills under consideration; and state legislatures in West Virginia, Kentucky, and Illinois have tightened their own laws. These responses have emphasised factors thought to have played a part in the Sago tragedy, including emergency oxygen supplies, tracking and communication systems, and deployment of rescue teams. There have also been proposals to increase the penalties for violations of safety standards.