Extraterrestrial activity was a leading theory: “IM SORRY WHAT???? THE SKY JUST TURNED BLUE???? literally so confused I think aliens just tried to steal new york,” one user wrote on Twitter.

“Apparently aliens are landing in New York City right now bcs the sky’s blue,” wrote another.

In this trying time, some saw the hand of God at work: “Don’t worry, New Yorkers. The blue light you saw in the sky was just the Rapture,” one tweet said.

Another Twitter user noted that people had been warned to change their ways: “What’s happening in the sky in New York? If it’s the rapture, I just wanna say I told y’all to quit it.”

Travelers at LaGuardia airport were treated to potential delays as well as a light show.

“Due to a power outage in Queens, there is partial flight operations @LGAairport. Many flights are departing, some are not,” the airport wrote on its Twitter account, later adding that power was back in “all terminals” and advising passengers to check with airlines for flight status information.

In the end, the explanation turned out to be somewhat more mundane than the end of times or invaders from outer space: a problem at a local power plant.

“The lights you have seen throughout the city appear to have been from a transformer explosion at a Con Ed facility in Queens. The fire is under control, will update as more info becomes available,” the New York Police Department tweeted.

Con Edison, the power company, tweeted that: “There was a brief electrical fire at our substation in Astoria which involved some electrical transformers and caused a transmission dip in the area. We’re currently investigating the cause of the incident.”

“The incident is under control. There are no injuries reported, and no fire,” the fire department said.

The anticlimactic explanation was disappointing to some.

“I wish the blue sky in New York was aliens and not a power plant on fire,” one Twitter user wrote. CC