Russian opposition leader Alexei Navalny died Friday in a remote penal colony in Russia’s far north, the country’s prison service announced without giving the cause of his death. News of his death flooded across Russian Telegram news channels and was confirmed in a curt announcement by prison authorities, prompting the U.N. Human Rights Office to call for an independent investigation. Navalny’s wife, Yulia Navalnaya, called on “all the people in the world” to stand up for her husband. “We should fight this horrific regime in Russia today,” she said at the Munich Security Conference on Friday after Vice President Harris’s speech there.