First bushfires of the season under control High temperatures and warm winds across northwest Sydney where bushfires are burning have eased. A significant part of Sydney's northwest is under threat from bushfires that have claimed two houses. NSW Rural Fire Service volunteers fight a fire within metres of homes at Windsor Downs, near Richmond in western Sydney. EASING conditions have helped firefighters control bushfires that raged through Sydney's greater west. NSW Rural Fire Service Commissioner Shane Fitzsimmons says all fire alerts have been scaled back and there are no longer any emergency warnings. "Conditions have moderated considerably but there's still a lot of work to do," he told ABC radio today. The RFS wasn't ruling out that the fires had been deliberately lit or were the result of backburning. "We have a number of fire specialists and police officers that will be out there this morning ... and they'll be doing investigations into cause and origin," Mr Fitzsimmons said. It's fair to say that in the Winmalee area there was a burn last week ... whether this fire is a direct result of that is what the investigators will be focusing on today. More than 63 fires were burning across the state on Tuesday with more than 40 uncontrolled at any time, he said. A home was lost at Marsden Park, in Sydney's west, and a shed destroyed near Castlereagh, where a fire raged through about 60 hectares of dry bush. Another house was initially reported destroyed at Winmalee but it was later found to have been saved, Mr Fitzsimmons said. Mr Fitzsimmons said hazard reduction burns were carried out in the area last week into the weekend, but he didn't know if any occurred on Tuesday. "I'm not aware that anyone was out there actively conducting hazard reductions yesterday, particularly in light of those conditions," he said. The RFS was in ``constant conversation" with other agencies carrying out hazard reduction burns. "All the stakeholders in fire management work together ... they prioritise where the risks are, what the treatments and the programs are to address that risk," Mr Fitzsimmons said. He said conditions on Tuesday ``exceeded what was forecast and presented that real challenging weather. "It is a stark reminder that summer is around the corner and when the weather ingredients are right you've got a recipe for fires to start quickly and start easily," he added.