Seven men have finally been convicted over the world's worst industrial disaster, the gas leak in the Indian city of Bhopal.Toxic gas leaked out of a chemical factory in 1984, killing thousands overnight and many thousands more in the following years. But for many it is too little, too late. Many victims lost their families and their health. And now they are furious that they appear to have lost their battle for justice. Al Jazeera's Nilanjan Chowdhury reports.