Hong Kong’s picturesque skyline was again hidden behind smog as air-pollution levels in the city peaked this week, Wall Street Journal reports.

According to Thursday readings, the air-pollution index reached 212 (effectively a 5 out of 7 on a local standard scale, meaning that healthy people will be noticeably affected) the second-worst pollution levels of any major Chinese city. The government has warned its citizens with heart or respiratory illnesses to stay inside. Those who went to work braved the toxic air with surgical masks. Hong Kong boasts one of the most scenic skylines, but pollution had deprived many of the view. Andrew Shum, an employee working on the 36th floor of a skyscraper in Wan Chai, told the Journal, “You pay top dollar in office rent, but you can’t see a thing”.

Monitoring stations blamed the nearby typhoon which trapped pollutants resulting in the condensed haze that enveloped the city. Environmental activists urged the government to address the root issues such as car emissions. Mainland China recently announced its plan to close coal-fired power plants by 2015.