Smoke from Canadian wildfires shrouded New York in a record-breaking apocalyptic smog on Wednesday as cities along the United States’ East Coast issued air quality alerts and thousands evacuated their homes in Canada.

The Big Apple’s mayor urged residents to stay indoors as the thick haze of pollution cast an eerie yellowish glow over Manhattan’s famous skyscrapers, delayed flights and forced the postponement of sporting events.

Canadian oil and gas producer Crescent Point Energy Corp on Monday said it had brought back online full production volumes at its operations in the Kaybob Duvernay play that were shut in due to the wildfires in Alberta in the past few weeks.

Several other operators in Alberta have also resumed partial production after rainfalls helped stop some of the wildfires in recent days.