One writer on Twitter reiterated that aliens were not attacking the city: "Dear Twitter, the aliens have not arrived in NY".
One commenter said: "Can someone explain why the sky in Brooklyn was lightning top bright blue?"
NYPD reports that a fire caused by the explosion is under control. And the Metropolitan Transportation Authority said in a tweet that No. 7 train had been disrupted by the power failures.
"Small, blue explosion near LaGuardia has knocked out power at the airport and surrounding area, ' said user Mason Mccoy".
In the end, the explanation turned out to be somewhat more mundane: a problem at a local power plant.
Flights at La Guardia airport were grounded, traffic around the city was affected, and there were neighbourhoods without any power. The New York Police Department reiterated as much in a tweet, saying the blue light was the result of a "transformer explosion" and adding that "the fire is under control".
However, the bright blue beams that lit up the sky certainly caught the attention of nearby residents, who shared the shocking images on Twitter.
And even the 43rd Precinct of the NYPD couldn't help but poke fun at the possible alien invasion.
The official line on the blue light phenomena is that at around 9:12 p.m. Thursday night there was an electrical surge, followed by an explosion, at a Con Edison substation in Astoria, Queens.
Smoke was seen by those close to the power plant, however, the bright light was visible from as far away as Manhattan.
An electrical fault is basically just an electrical current that isn't behaving as it should, and Con Edison is still investigating what caused the fault in this case.
The power went down briefly at LaGuardia Airport, forcing a ground stop and causing delays. "THE SKY JUST TURNED BLUE???? literally so confused I think aliens just tried to steal NY", one user wrote on Twitter.