Energy Secretary Jericho Petilla says a malfunction in a power plant in Lanao del Norte caused the massive blackout in Mindanao on Thursday. Petilla said their initial investigation showed the problem occurred at the Agus 1 power plant. He added they are still determining if the disruption was due to a tripped power plant or if it was a transmission problem. ANC Dateline Philippines, February 28, 2014
