Described last year by India's prime minister as a tragedy that "still gnaws at our collective conscience", the 1984 Bhopal gas leak is the world's worst industrial accident.
A lethal plume of methyl isocyanate (MIC) gas escaped from a storage tank at the Union Carbide pesticide factory in the early hours of December 3, 1984 in Bhopal.
Investigators concluded that water leaked into the tank, causing a reaction that triggered the release. One study suggests sabotage could have been to blame.
MIC is a highly toxic, sharp-smelling gas used in the production of pesticides, rubber and adhesives.
THE COMPANY AND PLANT
Union Carbide India Limited (UCIL) was a 51-percent-owned unit of US corporation Union Carbide. Union Carbide sold its stake in the Indian company in 1994 and was then acquired itself by conglomerate Dow Chemical in 1999.
The plant was built in the 1970s in the centre of Bhopal and was surrounded by slums and other low-grade residential buildings.
THE DEATH TOLL
Government figures put the death toll at 3,500 within the first three days but independent data by the state-run Indian Council of Medical Research (ICMR) puts the figure at between 8,000 and 10,000 for the same period.
The ICMR has said that up to 1994, 25,000 people also died from the consequences of gas exposure.
Union Carbide settled all liabilities related to the accident, including cleaning up the site, with a 470-million-dollar out-of-court settlement with the Indian government in 1989 after years of wrangling about the amount.
The Indian government had initially demanded 3.3 billion dollars.
Today, many survivors living close to the Union Carbide facility say they have seen none of the compensation meant to help those affected.
In order to claim money, survivors had to prove their ailments -- including kidney problems, cancer and respiratory illnesses -- were caused by the toxic cloud that belched from the plant.
The International Campaign for Justice in Bhopal (ICJB), an umbrella group of survivors' organisations, says most survivors received 25,000 rupees (500 dollars) to fund a lifetime of hospital visits.
Relatives of those killed were paid an additional 100,000 rupees for each family member who died.
THE COURT CASES
In the United States, Union Carbide has been unsuccessfully pursued with civil and class-action suits for compensation. Several cases are still in the appeals process.
In India, a local court in Bhopal on Monday convicted the then top Indian executives of UCIL, including chairman Keshub Mahindra, managing director Vijay Gokhale, vice president Kishore Kamdar and plant superintendent K.V. Shetty.
The convicts were granted bail and are expected to appeal.
A second criminal case pending in the same court in Bhopal was filed jointly four years ago by seven pressure groups which have charged Dow Chemical and UCIL of contaminating the environment with chemicals.
There are also countless civil cases pending in Indian courts.
Survivors still suffer from ailments such as respiratory and kidney problems, hormonal imbalances, mental illness and forms of cancer.
New generations have been made ill by the polluted groundwater and poisonous breastmilk fed to them from birth.
To this day, children are born grotesquely disfigured, with webbed hands and feet, weak immune systems, stunted growth and congenital disorders.
Campaigners say areas around the now ramshackle and deserted factory -- that still stands in the city as a permanent reminder of the disaster -- remain contaminated.
Inside the building, dozens of bottles of chemicals are still stocked in the factory's lab, covered in dust and cobwebs and surrounded by broken glass.
Emergency instructions and a sticker reading "safety is everybody's business" still hang on the wall.