Authorities have not yet determined the exact cause of the explosion. Although they investigators initially suspected that the boiler was faulty, they later said they were looking into a possible gas leak...It has also emerged that highly flammable chemicals were stored in the factory that produces packaging materials for tobacco companies and Swiss food conglomerate Nestle. The accident occurred right as the night shift was handing over to the morning shift, resulting in an unusually high number of workers being present....German news agency DPA reported that the father of one of the deceased had filed suit against the factory's owner, Syed Mokbul Hussain, a former lawmaker, and eight others for culpable homicide.