New York was eerily orange on Wednesday as smoke shrouded the city. The haze drifted in from wildfires raging in Quebec, some 500 miles away, wreaking havoc on air quality across the Northeast US.

The smoke was so thick, New York City briefly ranked as the most polluted city in the world. The Environmental Protection Agency issued its highest warning for pollution, a “Code Maroon” for hazardous air quality. The pollution was record-shattering on Wednesday, with an air quality index score of 392 around 4PM ET for fine particles beating a record of 174 set a day earlier (according to the EPA’s records, which started in 1999, The New York Times reports). 

Fine particle pollution is especially worrying because it’s small enough to enter the lungs and can even make its way into the bloodstream. Moreover, particles in smoke have been found to be up to 10 times more harmful to human health than pollution from other sources like vehicles and factories.

Officials advised people to stay indoors, emptying many streets in a way the city hadn’t seen since the height of the covid-19 pandemic. Schools called off field trips and other outdoor activities. The Federal Aviation Administration delayed flights due to poor visibility. New York City’s skyline, obscured by smoke, was barely recognizable via EarthCam. 

The Verge snapped some photos of the apocalyptic scene in the Big Apple — from amber skies to desolate streets. To stay updated, you can follow the EPA’s air quality monitoring tool AirNow. Its forecast for Thursday is still bad — not quite a Code Maroon (hopefully) but a Code Red for “unhealthy” air.