Fifteen Indian workers were feared trapped on Tuesday after a blast caused by a suspected gas leak in a tunnel at a hydroelectric project in the rugged state of Sikkim killed 10, authorities said. Monday’s incident took place at state-owned National Hydroelectric Power Corp’s (NHPC) project on the Teesta river in the northeastern state’s village of Samardung, district official Subash Ghimirey said. A sudden burst of gas suspected to be methane trapped or embedded in rocks in the tunnel caused...