Mumbai, April 10 -- Four young men from Virar East who were employed by a private contractor died on Tuesday when they were working inside a 30-foot-deep sewage treatment plant. The workers were undertaking a clean-up operation at the plant in Virar West, and they likely died of suffocation, said the police. But the father of one of the victims alleged his son, an electrician, died of electrocution and not suffocation, and demanded a fair probe into the incident. Police have arrested Mahadev Kupte, a supervisor with Polycom, on charges of culpable homicide not amounting to murder....