On February 7, 2009 as many as 400 brushfires rushed through the Australian region of Victoria, the country's second most populous state. The inferno — the worst in Australia's history — scorched 1.1 million acres of land, killing 173 people and injuring hundreds more. After the fires were finally contained one month later, scientists speculated on the cause, including climate change, the historically dry and drought-prone region and multiple days of 100°F (38°C) temperatures. Those who suspected it was arson were tempered by the realization that even an unintentional flick of a mostly flame-free cigarette butt could have caused a fire in those conditions.