In yet another accident involving the Navy, one civilian worker was killed and two injured in an accident at the under-construction nuclear submarine at the shipbuilding centre of Eastern Naval Command here on Saturday night. The incident took place when the pressure of the hydraulic tank of the Arihant-class submarine was being tested and the tank’s lid fell on the workers of L&T at Building-5 of the shipbuilding cente, DRDO chief Avinash Chander said. 24-year-old Amar was killed while Amzad Khan and Vishnu were seriously injured.