Members of the doomsday cult Aum Shinrikyo punctured plastic bags of liquid sarin with sharpened umbrella tips on five separate subway cars converging near Kasumigaseki station, the seat of Japan's government. Thirteen people died and more than 6,000 sought medical treatment, many suffering blurred vision, vomiting and convulsions. The attack shattered Japan's sense of public safety and exposed a cult that had stockpiled chemical weapons and recruited scientists from top universities.
The trains were chosen deliberately: all five converged on Kasumigaseki, the government district of Tokyo, during the peak of morning rush hour. Cult members carried sarin in plastic bags wrapped in newspaper, dropped them on the floor, and punctured them with the sharpened tips of umbrellas before stepping off at the next stop.
Commuters staggered off trains coughing, bleeding from the nose, and collapsing on platforms. Station attendants who tried to clean up the mysterious liquid were themselves poisoned. Emergency rooms across Tokyo filled with patients exhibiting symptoms doctors had only read about in textbooks on chemical warfare.
The investigation that followed unraveled Aum Shinrikyo, led by the half-blind guru Shoko Asahara, revealing a compound where chemists and doctors defected from prestigious careers to manufacture nerve agents and even attempted to produce biological weapons. Asahara was executed in 2018. The attack remains Japan's deadliest act of domestic terrorism and reshaped how the country policed religious cults and prepared for chemical emergencies.