The busted transformer serves the cities and provinces in Southern and Central Mindanao, including this metropolis, the cities of General Santos and Cotabato, and parts of Bukidnon and the Autonomous Region in Muslim Mindanao.
Napocor officials immediately ruled out sabotage in the power outage. This, as intelligence reports revealed renewed threats of terrorism, particularly here and in Cagayan de Oro City.
The explosion of the Saguia—ran transformer, located at the Agus 2 hydroelectric plant, resulted in a systems loss and tripping of transmission lines serving the affected areas.
The incident also caused the tripping of the 138-kilovolt Lines 1 and 2 of the Agus 2-Kibawe, thus cutting off power to Southern and Central Mindanao, Napocor said.
"It was beyond human control in spite of the fact that we have been religiously implementing our maintenance program," said a Napocor official, adding that such explosions are, indeed, very rare.
Davao City residents were particularly alarmed because the power outage took place just two days after Mayor Rodrigo Duterte raised the terror alert here a notch higher to "orange," the second highest in a scale of five security alerts.
Duterte called on city folk to be extra vigilant. Two powerful blasts shook this southern metropolis last year, leading to the creation of the military-led Task Force Davao.