An explosion at an electrical power station in New York City on Thursday evening lit up the sky with an eerie blue light - and triggered a flurry of speculation on social media.
Some wondered if aliens had landed.
Others thought something supernatural might be to blame for the ghostly glow.
ATTENTION EVERYONE IN THE NEW YORK AREA— Herb Marselas (@HerbMarselas) December 28, 2018
Your superpowers will begin to develop over the next few days
Please do not choose any superhero names that are copyright Marvel or DC
Others wondered if the hand of God was at work over New York, heralding perhaps a new Pope, or the moment when Evangelicals say true believers will be swept up, or "raptured", to heaven.
congrats to astoria on electing a new pope— Sopan Deb (@SopanDeb) December 28, 2018
I think the rapture has started in New York... pic.twitter.com/j1acPcQo9x— Okoye’s Spear (@Willi_Mae) December 28, 2018
The New York Police Department took to Twitter to reassure the public that the strange light was caused by something much more down to earth - a transformer explosion at a Con Edison power station in the Astoria neighbourhood of the borough of Queens.
And Con Edison shed more light on the cause of the excitement.
There was a brief electrical fire at our substation on 20th Avenue & 32nd Street in Astoria this evening, which caused a transmission dip in the area. All power lines serving the area are in service and the system is stable. Photo: Michael Friedl, New York Times pic.twitter.com/vq2Ao46rhk— Con Edison (@ConEdison) December 28, 2018
Meanwhile, the power cut hit New York's LaGuardia Airport, which warned travellers to be prepared for delays.
Due to a power outage in Queens, there is partial flight operations @LGAairport. Many flights are departing, some are not. Please check flight status with carrier.— LaGuardia Airport (@LGAairport) December 28, 2018
The blue colour comes from the way electricity passes through air, correspondents say.
Electrical energy will knock electrons off atoms in the gases that make up the air.
When these electrons recombine with the excited atoms, returning them to their starting energy state, light is emitted.
The colour of the light emitted depends on the type of atoms involved.
A blue colour is associated with oxygen atoms; pink/purple colours are associated with nitrogen atoms. Oxygen and nitrogen are the gases that dominate the air we breathe.