QUETTA: Quetta City plunged into dark early Monday night. Supply was restored after an hour. QESCO sources told PPI that due to technical fault Quetta grid and Sariab grid tripped tonight due to technical fault. Fault was removed after an hour and Quetta Grid was made functional. Efforts were underway to run Sariab grid. Suddenly disconnection of supply badly affected work at hospitals, newspaper and news agencies offices.