Today in history, December 3: Bhopal gas leak kills thousands in world's worst industrial accident
Two men carry children blinded by the Union Carbide chemical pesticide leak to a hospital in Bhopal, India on December 5, 1984. (AP: Sondeep Shankar)
It started with a cloud of gas in the dead of night, silently submerging the city in a toxic soup.
By morning on December 3, 1984, Bhopal in central India awoke to the nightmare its residents are still living today.
A storage tank on the city's outskirts, owned by Union Carbide India's pesticide plant, had leaked extremely toxic methyl isocyanate gas at an alarming rate: 40 tonnes within two hours. Wind quickly spread it far and wide across the city.
More than 500,000 people were exposed in what is widely considered to be the world's worst industrial accident.
Thousands died in the first hours after the leak.
The ABC spoke to activist Satinath Sarangi in 2014. He arrived in Bhopal the day after the leak and saw people struggling to breathe and a community reeling.
"The two things I remember most from the immediate aftermath of the disaster was just the magnitude of it; the number of people we saw who were in terrible pain, and the helplessness," he told the ABC.
"But most of all that there were so many ordinary people coming out to help the victims."
Like many industrial incidents on this scale, the damage on day one of the crisis was just the start. The ongoing fallout has been huge — and the fight for justice and compensation has been far from simple.
Firemen hose canvas screens to prevent the spread of dangerous fumes at the Union Carbide plant. (AP: Peter Kemp)
Thousands killed over years
At 1am, the company's two emergency sirens had sounded — one inside the plant, and one to alert the surrounding city. However, the second was quickly turned off: it was company policy not to alarm residents.
Later that morning, the extent of the catastrophe became clear. Bhopal's hospitals and morgues were soon overrun. Mass funerals and cremations were necessary.
The first effects of exposure to methyl isocyanate — which many companies had already phased out of their production processes by 1984 — include coughing and eye irritation, a feeling of suffocation and lungs burning, breathlessness and vomiting.
Because the gas is twice as dense as air, it falls towards the ground, which means children likely inhaled a higher concentration.
According to government estimates, around 3,500 people died in the days following the leak, but the disaster has had a long tail.
By 2024, an estimated 22,000 people had died due to direct exposure to the leak, according to an Amnesty International report.
Many survivors continue to suffer side effects today — from eye and respiratory illness, neurological impairment and PTSD. Neonatal death rates have increased, along with more miscarriages and stillbirths in mothers who had been exposed.
An Amnesty International report from 2024 said that the gas leak pushed already impoverished communities into "further destitution", with women and children suffering disproportionately, particularly where the main wage earner died or became too ill to work.
"The gas leak is not the only chemical catastrophe affecting Bhopal's communities. Thousands of tonnes of toxic waste remain buried in and around the abandoned plant to this day," it said.
Bhopal is still plagued with the environmental fallout left by the plant, called a "second disaster" by Amnesty International. Ongoing contamination from the abandoned plant continues to affect groundwater and land around Bhopal.
Victims of the Bhopal gas tragedy hold posters during a demonstration outside a court in 2010. (Raj Patidar: Reuters)
Only seven men prosecuted
Survivors and families of the dead have fought for justice and compensation from the early days after the catastrophe.
By 2003, compensation had been awarded to more than 550,000 people for injuries received and 15,000 survivors of those killed, according to the Bhopal Gas Tragedy Relief and Rehabilitation Department. The average amount given to families of the dead was US$2,200.
Court action has been ongoing over the past 40 years.
The plant's American parent company, Union Carbide Corporation (UCC), faced legal proceedings soon after the tragedy.
The Indian government refused the company's initial offers of compensation and claimed US$3.3 billion, but eventually agreed to an out-of-court settlement for US$470 million.
UCC CEO Warren Anderson travelled to India immediately after the leak with a technical team, and was placed under house arrest before being released.
He was charged with manslaughter in 1991, and later declared a "fugitive from justice" after not appearing in court. The US declined to extradite him to India. He died in 2014.
In 2010, seven former employees of the company's Indian subsidiary were convicted of causing death by negligence — they were sentenced to two years' jail and fined 100,000 rupees (about $1,700), but were soon released on bail.
At the time, human rights groups said the verdict — seen by many as merely symbolic — was inadequate.