Police enter a cafe after a hostage siege in the central business district of Sydney on December 16, 2014. (WILLIAM WEST/AFP/Getty Images)

A frightening siege in Sydney, Australia ended after more than 16 hours when police stormed the Lindt Chocolate Cafe, where a gunman had taken customers and employees hostage early Monday morning. Three people were killed, including the gunman, and four more were injured.

Police identified the gunman as Man Haron Monis, an Iranian-born man with a criminal record who was known to authorities. “The siege had transfixed Australia since Monday morning, when the armed man took control of the cafe in central Sydney, with an unknown number of employees and customers trapped inside,” the New York Times reports. The man was carrying a black flag with white Arabic script similar to those used by Islamic militants on other continents, and the flag was later displayed in the window of the cafe.”

During the siege, which the international community followed along with overnight via Twitter, Sydney residents banded together in a variety of creative ways. One of the most inspiring efforts—which quickly went viral—was the social media hashtag #Illridewithyou, which Sydney-siders used to show solidarity with fellow residents wearing Muslim religious dress, and help them avoid potential anti-Muslim backlash.

A joint-prayer session between a rabbi, priest, and imam was held during the siege at Sydney’s Lakemba Mosque