RECAP: An overview of two major fires in the South West

The fire began in the morning of Thursday, December 9 with hot weather conditions and a northerly wind which Mr Lullfitz said spread into surrounding vegetation and then into the national park.

Emergency service crews were not diverted from the already raging fire further south in Caldardup.

"We had extra crew on standby just in case something like this happened," Mr Lullfitz said.

As the fire spread into bushland, the Department of Fire and Emergency Services issued an emergency warning.

Parts of Quinninup and Tilly Roads were closed and people were told to get out of the area in order to survive.

Mr Lullfitz said the weather conditions were the most challenging part of battling the fire.

He said with crews already fighting a major blaze in Margaret River's Boranup region, they were stretched but had just enough resources to contain the blaze.

Another challenge was that because of the limestone cave system in the area, the fire fighters were not allowed to use heavy machinery.

"So we had to burn out an area to reach an existing fire break which meant it took longer to get fire under control," Mr Lullfitz said.

Other than the initial structure fire, no other property was damaged.

"It was a really challenging couple of days but at the end of the day a big area burnt -171 hectares, but could have been much worse," Mr Lullfitz said.

The fire was downgraded to an advice warning late on the Thursday and Mr Lullfitz said crews were still mopping up to ensure the area was safe and contained.

Late on Monday afternoon, the fire was given the all clear from DFES.

WA Police are calling for information after an initial assessment of the Boranup bushfire scene suggests the blaze was deliberately lit.

The fire broke out on the morning of Wednesday, December 8 and quickly took hold in dense forest, fanned by hot, gusty winds.

Water bombers helped firefighters from the air until darkness fell, leaving the battle at ground level until first light on Thursday.

An evacuation centre was established in Margaret River with the community able to attend meetings from emergency services for the latest updates.

Another day of extreme winds and warm weather saw the fire warning zone increase dramatically, covering much of the South West capes region as far south as Cape Leeuwin.

Cooler conditions over Friday and the weekend allowed crews to conduct vital containment work, allowing the fire to be brought under control.

As fire conditions eased, investigators from Strike Force Vulcan began to assess the scene.

"Based on an initial assessment of the fire scene it is believed the fire was deliberately lit, and may have been ignited near Mammoth Cave," a police spokesperson said.

Mammoth Cave is accessed via Caves Road and is near the border of Boranup and Forest Grove suburbs.

The fire burnt through around 7,800 hectares of the Leeuwin Naturaliste National Park and was brought under control early on Monday, December 13, following a significant fire response led by local and out of area volunteers and personnel from DFES and the Department of Biodiversity, Conservation and Attractions (Parks and Wildlife Service).

Detectives are calling for anyone who saw suspicious activity in the vicinity of Mammoth Cave on Wednesday or has information regarding the bushfire to contact Crime Stoppers on 1800 333 000 or report online at www.crimestopperswa.com.au

Anyone who has dash-cam or mobile phone vision of people or vehicles in the area at the time can upload the vision via: wapf.au.evidence.com/axon/citizen/public/margaret-river-region-bushfire

WA Police said rewards were available for information that leads to the identification and conviction of an arsonist.

For full coverage of the recent South West fires, visit busseltonmail.com.au