I don't think it was uncommon, at least not for power outages. Here's a Washington Post article from 1977 that uses it: https://www.washingtonpost.com/archive

I don't think it was uncommon, at least not for power outages. Here's a Washington Post article from 1977 that uses it: https://www.washingtonpost.com/archive/politics/1977/07/15/blackout-paralyzes-new-york-city-for-day/eb6f9906-db2c-4561-9ca9-f3d054f01c08/ https://www.washingtonpost.com/archive/politics/1977/07/15/b... And a NY Times article from later in 1977: https://www.nytimes.com/1977/10/17/archives/around-the-nation-fire-at-electricity-plant-blacks-out-san-antonio.html https://www.nytimes.com/1977/10/17/archives/around-the-natio...