Sarin Gas Attack

In March 1995, Tokyo underground passengers suffered a devastating terror attack. Sarin gas was released into three of the Tokyo Metro trains, making over 5,000 victims and eventually leading to 12 deaths.

1995年3月25日、オウム真理教徒の手により綿密に 計画され実行に移された地下鉄サリン事件。サリンガ スは東京メトロの計3線において解放され、5000人 を超える被害者と12人の死者を出す結果となった。

Tokyo is a low-crime city and when the gas attack happened, it seemed like no one was prepared for such a large scale emergency. Yet Aum Shirinkyo, the religious sect perpetrating the attack, was well known to Japanese police services. Just nine months before the Tokyo attack, members of the cult had spread sarin gas in the city of Matsumoto, causing instantaneous death by respiratory arrest in 4 victims.

Infuriatingly enough, Tokyo policymakers and the Japanese government did not take notice of this warning and failed to establish an appropriate emergency response preparedness strategy.

The purpose of this information map is to convey the timeline of the attack, as well as to pinpoint some of the major problems that occurred in the course of the various emergency responses.

In spite of immediate passenger reactions, the Tokyo Metro company failed to put infected trains out of service soon enough, obsessed as it was with running its service on time. Once contaminated with the nerve agent, trains kept rolling for up to 40 stops before being stopped and evacuated.



The sarin antidote (pralidoxime) was generally not in stock at Tokyo hospitals, and even if it was, could not be administered without accurate information on the nature of the gas. Most victims were given basic symptomatic treatment, while critical and severe cases were administered diazepam against seizures, and atropine sulfate as antidote.

Health services in Tokyo had never studied the 1994 Matsumoto attack report, and were uninformed about sarin poisoning. It was only thanks to media reports on television that Matsumoto physicians, having recognised the symptoms, could send out crucial information to their peers in the capital.


Sarin is a powerful chemical warfare agent. This was considered the most serious attack upon Japan since World War II.

Surveys conducted with the victims in 1998 and 2001 showed that many were still suffering from post-traumatic stress disorder. Over sixty percent reported chronic eyestrain and a decrease in vision.

Addressing such a serious issue through a seemingly innocent illustrated map style was a challenge. I would like to thank Sachiko Tashiro for her advice, and her help with the Japanese translations.

View the map in PDF

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