there was no widely known incident where an entire city experienced the sky turning green and people going into panic due to such an event. It's possible that such an event could occur , or it could be a fictional scenario or a localized incident that has not gained widespread attention.
If you have seen or heard about an event like this happening, I would recommend checking reliable news sources or conducting an internet search to find more information about the specific incident, including the date, location, and cause of the phenomenon. Remember that accurate and up-to-date information is essential when discussing real-world events.