Critical infrastructure sectors are defined by the Department of Homeland Security (DHS) as, "the physical and cyber systems and assets that are so vital to the United States that their incapacity or destruction would have a debilitating impact on our physical or economic security or public health or safety." The sectors that fit this classification per the Cybersecurity and Infrastructure Security Agency include the chemical, commercial facilities, communications, critical manufacturing, dams, defense industrial base, emergency services, energy, financial services, food and agriculture, government facilities, healthcare and public health, information technology, nuclear reactors/materials/waste, transportation systems, water and wastewater systems sectors.