Victims of the 1984 Bhopal gas tragedy carry an effigy symbolising a group of ministers and union and state government representatives, and a poster of former chairman of the US company Union Carbide Corporation Warren Anderson, during a demonstartion on the eve of the 28th anniversary of the disaster, in Bhopal, yesterday. A gas leak at the Union Carbide Corporation plant in Bhopal in 1984 killed at least 15,000 people in what is considered the world’s worst industrial accident.