The Federal Coal Mine Safety Act of 1952 is a U.S. law authorizing the federal government to conduct annual inspections of underground coal mines with more than 15 workers, and gave the United States Bureau of Mines the authority to shut down a mine in cases of "imminent danger." The Act authorized the assessment of civil penalties against mine operators for failing to comply with an order to shut down (a "withdrawal order") or for refusing to give inspectors access to mine property. The law did not authorize monetary penalties for noncompliance with the safety provisions. In 1966, Congress extended coverage to all underground coal mines.