The leakage Timeline, summary
At the plant[1][2]
• 21.00 Water cleaning of pipes starts.
• 22.00 Water enters tank 610, reaction starts.
• 22.30 Gases are emitted from the vent gas scrubber tower.
• 00.30 The large siren sounds and is turned off.
• 00.50 The siren is heard within the plant area. The workers escape.
Outside[1][2]
• 22.30 First sensations due to the gases are felt — suffocation, cough, burning eyes and vomiting.
• 1.00 Police are alerted. Residents of the area evacuate. Union Carbide director denies any leak.
• 2.00 The first people reached Hamidia hospital. Symptoms include visual impairment and blindness, respiratory difficulties, frothing at the mouth, and vomiting.
• 2.10 The alarm is heard outside the plant.
• 4.00 The gases are brought under control.
• 6.00 A police loudspeaker broadcasts: "Everything is normal".