CHICAGO — Twitter has been a way for people to keep track of tornado watches, train delays, news alerts or the latest crime warnings from their local police department.

But when the Elon Musk-owned platform started stripping blue verification check marks this week from accounts that don’t pay a monthly fee, it left public agencies and other organizations around the world scrambling to figure out a way to be trusted.

High-profile users who lost their blue checks Thursday included Beyoncé, Pope Francis, Oprah Winfrey and former President Donald Trump.

But it also included accounts for major transit systems from San Francisco to Paris, national parks like Yellowstone and official weather trackers.