District Issues Protective Actions for Electricity Shortages An electricity shortage can cause rolling blackouts or unplanned blackouts throughout the city. Blackouts can last from seconds to days. In general, if there is an electricity shortage you should: Store essential supplies, such as, flashlights, batteries, a portable radio, water, non-perishable foods and a manual can-opener. Turn off lights, heater/air conditioner and other appliances when you leave your home. Conserve electricity when possible. If the electricity turns off, use a flashlight--DO NOT use candles. DO NOT use a generator inside a home or garage.  Listen to local radio or television for updated information.