Cooler temperatures on Monday came to the aid of more than 2,000 firefighters battling to contain a blaze north of Los Angeles which has burned some 12,000 hectares and forced the mandatory evacuation of more than 3,000 people, according to dpa. The so-called Powerhouse Fire ignited late Thursday in the Angeles National Forest, destroying nine homes and threatening 1,000 more in an area some 100 kilometres north of the city, according to the Los Angeles Times. Firefighters had the blaze about 40 per cent contained Monday, helped by the cooler temperatures, higher humidity and gentler winds that replaced the scorching conditions at the weekend. The fire was the second major blaze this summer in southern California, which is bracing for a severe burn season following an unusually dry winter.