Meralco energy management head Nixon Hao said the isolated brownouts may be brought by system overload and breakdowns. "Although Meralco regularly upgrades and maintains its facilities so these operate in the best condition, there may be instances when some areas within the Meralco franchise may experience some power interruptions caused by circumstances beyond its control," Hao said. During the Holy Week, Meralco reported that power supply was steady except for minor and localized power outages in some areas particularly in Grace Park in Caloocan City; some parts of Malabon, Pasay, San Juan and Sta. Mesa; Tondo, Sampaloc and Pandacan in Manila. These short duration power interruptions were brought about by automatic load dropping (ALD) situations wherein Meralco loads at chosen areas are shed automatically for the system to cope with the sudden outage of a power plant.