By Rob Taylor CANBERRA, Jan 17 (Reuters) - Bushfires burning out of control destroyed homes and cut power to Australia's second largest city as firefighters braced on Wednesday for worse to come. A major fire swept into the hamlet of Toombullup in southern Victoria state overnight, levelling at least seven homes. Another house was lost in rugged mountains west of Melbourne, a city of about 4 million people. "It was really torrid. The fire really took a big run last night in very dry, very hot, very windy conditions," Environment Department spokesman Pat Groenhout told local media. Bushfires, many sparked by lightning, have blackened more than 1.1 million hectares (4,247 square miles) of Victorian bushland since November, while blazes have also struck four other states. Australia on Monday asked for help from U.S. firefighters who will next week join volunteers from Canada and New Zealand helping battle the firestorms fuelled by higher temperatures and global warming. The Victorian blazes caused major power outages in Melbourne, leaving hospitals in the dark and causing road chaos as temperatures climbed above 40 Celsius (104 Fahrenheit) on a day in which power demand hit a new record peak of 8,950 megawatts. Electricity firms said up to 200,000 customers across the state were affected after fires tripped safety cut-outs. Groenhout said worse lay ahead with at least another week of extreme temperatures expected. "We've had four new fires started as a consequence of a band of lightning which moved through the state overnight," he said. The state government said it could impose restrictions on power use to limit demand, ruling out use of air conditioners. At least seven communities, Groenhout said, were under immediate threat on Wednesday from ember showers fanned by strong winds, saying firefighters faced an almost impossible task to prevent more homes being lost. Australia faces extreme fire danger this summer because of severe drought. Bushfires, a regular feature of the summer, have killed more than 250 people over the past 40 years.
