Back in 1995, six years before the terror attacks of September 11, 2001 would catapult terrorism to the forefront of the global conversation, another terror group attempted an attack that had the potential to dwarf even the immense loss of human life seen on 9/11.

On March 20, 1995, five members of the Japan-based doomsday cult Aum Shinrikyo entered the bustling Tokyo subway system at intentionally chosen locations carrying plastic bags full of a chemical agent known as Sarin. Once aboard the crowded commuter trains, each of the suspects punctured the bags and left them, fleeing the subway immediately and inoculating themselves against the effects of the gas from pre-positioned getaway vehicles.

The Sarin used, fortunately for the people of Tokyo, was not as powerful as it could have been (at only 30% pure). All told, only 13 people died, 50 suffered severe injuries and thousands reported symptoms of exposure. Had the Sarin been as powerful as intended, however, thousands would likely have died.

The cult’s leader, a former conman named Chizuo Matsumoto that had adopted the moniker Shoko Asahara upon his transition to religious leader, had given the order to conduct the attack in hopes that it would usher in the apocalypse he had prophesied. Upon raiding his compound, police found the apparatus required to produce the Sarin, as well as the nerve agent VX, the attempted production of botulinum toxin, and facilities for the last scale production of LSD, which the cult used as a part of their religious practices.

Asahara was among thirteen members of the cult that were sentenced to death for their roles in the subway attack, though the incident in Tokyo was not the only time Asahara or his group were implicated in murders. In 1989, Tsutsumi Sakamoto, a lawyer who was pursuing a class action lawsuit against the cult was murdered alongside his wife and child, injected with potassium chloride as they were sleeping and then strangled. In June 1994, another Sarin attack carried out by the cult killed seven, and led to hundreds of others being hospitalized.

Subway passengers are taken on stretchers from ambulances outside a Tokyo hospital after falling victim of the nerve gas attack by the Aum Shinrikyo cult on a subway on March 20, 1995. | AP Photo/Chiaki Tsukumo, File

Asahara was ultimately charged with 17 crimes, including murder the illegal production of weapons and drugs. The cult had purchased all of the equipment to begin manufacturing AK-47s with the intent of arming their thousands of members, but at the time of his arrest, they had not managed to begin the process. After a trial that spanned eight years, Asahara was sentenced to death, though two more years of appeals would follow. By 2008, he had exhausted his options, the cult had changed names and distanced itself from its fallen leader, and there was nothing left to do but wait for the sentence to be carried out. In Japan, no forewarning is provided before executions and they are carried out in secret. Prisoners are often notified only hours before the execution is conducted.

Asahara and six other members of the cult all had their executions carried out by hanging last week, with six members remaining on death row.

“When I think of those who died because of them, it was a pity (my husband’s) parents and my parents could not hear the news of this execution,” Shizue Takahashi said to reporters. A widow of a victim of the Subway attack, she has since served as a victim’s group representative. “I wanted (cult members) to confess more about the incident, so it’s a pity that we cannot hear their account anymore.”