AN unattended electric fan triggered a fire in Cotabato City, gutting about 20 houses made of light materials in Barangay Poblacion 4, authorities said on Tuesday. Fire Chief Inspector Lucily Banac-Jusay, city fire marshal, said the Monday afternoon blaze was the first to hit the city this month. 'Nobody was hurt, all our firefighters were unharmed, no civilians were injured,' Banac-Jusay said. Henry Macion, village chairman of Poblacion 4, said the 3 p.m. fire started at the boarding house owned by Celso Celis and spread quickly to adjacent houses in Purok Martinez. 'We are still determining the real cause of the conflagration,' Banac-Jusay said, adding that initial estimates by investigators placed the extent of damage at P500,000. She reminded the public that all electric appliances should be unplugged when not in use to prevent fire. 'We highlight tips to prevent fire during this Fire Prevention Month (March), but our prevention actions must be year-round,' Banac-Jusay said.