It is twenty-six years since the Japanese terrorist group Aum Shinrikyo released the deadly nerve agent sarin in a series of five coordinated attacks on Tokyo's subway system.
Twelve people lost their lives in the aftermath of the incident on March 20th 1995. More than 5,000 civilians required medical attention, with some fifteen-hundred found to have been moderately to severely poisoned by the effects of the toxin.
Subsequent analysis of the harrowing events of that day would reveal a number of key lessons which continue to inform and guide authorities, responders and medical teams in their preparedness and response to chemical incidents.