An emergency warning has been downgraded on Thursday night, although authorities warn residents should remain on high alert for changing conditions. Emergency crews first responded to the fire about 10.15am, which had been burning sulphur and producing large amounts of smoke. The blaze was contained to the shed but heavy smoke continued to track in a southeast direction, authorities confirmed shortly after 2pm local time. Fire crews remained at the scene, where they worked to extinguish the fire and manage risks posed by the hazardous materials. "Heavy smoke was issuing from the building and crews immediately commenced firefighting activities, search and rescue and hazardous materials operations."