"The US energy sector consists of three interrelated segments: electricity, oil, and natural gas. The reliance of virtually all industries on electric power and fuels means that all sectors have some dependence on the energy sector. Information sharing is key to ensuring the protection of the national electrical infrastructure (electric grid) since the majority of it is privately owned. [...] A prolonged electrical outage will cause cascading effects to all other sectors. Emergency managers, owners and operators, and public safety personnel are encouraged to develop plans in advance, communicate priorities, and understand the effects of operating and maintaining services to each sector in the event of a mid- to long-term incident."
Office of the Director of National Intelligence: https://www.dni.gov/