Now that everyone in New York has been told that last night's spectacular light show over Astoria was not due to an alien invasion but rather a Con Ed transformer explosion, Con Ed would like you to know: It was not a transformer, and it didn't explode. Rather:
Last night’s electrical fault caused a sustained electrical arc flash & transmission disturbance. There were no injuries and all the power lines serving the area are stable. We apologize for the disruption to customers. Photo: Wall Street Journal. #Queens #Astoria pic.twitter.com/c6chBF4BFL
— Con Edison (@ConEdison) December 28, 2018
An "arc flash" is a short circuit where electricity jumps a gap between two parts of a circuit, causing the mother of all sparks to, in essence, set the air on fire. (The air technically ionizes, having its electrons forcefully stripped off of its atoms, but if by "on fire" you mean "gets superhot and creates a bright light" then you're within poetic license to call it "on fire.")
An arc flash is different from a transformer explosion in that no transformers are harmed in its making, but similar in that they both involve an overloaded circuit sending electricity somewhere it really shouldn't go.
This kind of incident, it turns out, is a fairly common occurrence in the city, even if the results don't usually lead to quite such an impressive sky display:
- In October 2017, a transformer on Cherry Street blew up with enough force that residents of neighboring Two Bridges apartments said they felt their buildings shake, though no power outages were reported.
- In May 2015, an apparent lightning strike caused a fire that led a transformer on Staten Island to explode, creating a power surge that knocked down a library wall at St. John's University's nearby campus.
- In January 2014, a transformer under Sixth Avenue in midtown blew up after being shorted out by salt and melting snow, causing some impressive (orange) flames and leading to the evacuation of a nearby building.
- Most famously, rising floodwaters from Hurricane Sandy in October 2012 led to a massive explosion at Con Ed's power plant at 14th Street and the East River, shutting down electrical service to nearly all of lower Manhattan and creating a pretty impressive blue flash of its own (though many New Yorkers were too busy fleeing rising seas to notice at the time).
- In July 2006, a series of cable failures in Astoria led remaining power cables — and, yes, transformers — to fail and catch fire, leading to a weeks-long blackout to much of northwestern Queens.
- In July 1977, the massive Ravenswood 3 power plant on the East River waterfront in Long Island City shut down under a power surge caused by a pair of upstate lightning strikes, which had caused a (wait for it) transformer near Indian Point to explode. The resulting citywide blackout entered New York legend.
Faults in electric equipment are relatively common: According to a Popular Mechanics post that it continually updates every time one of these things explodes, about 35 transformers alone fail every year in the city, though most of them don't catch fire or explode.
At least Con Ed can be proud that this time, unlike in 2006, it figured out the problem right away and fixed it before needing to go around handing out bags of ice. Thank goodness for small favors.