<P> The MIC gas leak emanating from tank E610 petered out at approximately 2: 00 a.m. Fifteen minutes later, the plant's public siren was sounded for an extended period of time, after first having been quickly silenced an hour and a half earlier . Some minutes after the public siren sounded, a UCIL employee walked to a police control room to both inform them of the leak (their first acknowledgement that one had occurred at all), and that "the leak had been plugged ." Most city residents who were exposed to the MIC gas were first made aware of the leak by exposure to the gas itself, or by opening their doors to investigate commotion, rather than having been instructed to shelter in place, or to evacuate before the arrival of the gas in the first place . </P> <P> The initial effects of exposure were coughing, severe eye irritation and a feeling of suffocation, burning in the respiratory tract, blepharospasm, breathlessness, stomach pains and vomiting . People awakened by these symptoms fled away from the plant . Those who ran inhaled more than those who had a vehicle to ride . Owing to their height, children and other people of shorter stature inhaled higher concentrations . </P> <P> Thousands of people had died by the following morning . </P> <P> Primary causes of deaths were choking, reflexogenic circulatory collapse and pulmonary oedema . Findings during autopsies revealed changes not only in the lungs but also cerebral oedema, tubular necrosis of the kidneys, fatty degeneration of the liver and necrotising enteritis . The stillbirth rate increased by up to 300% and neonatal mortality rate by around 200% . </P>

In 1984 the bhopal gas tragedy took place because methyl isocyanate