Rebuilding a roadhouse pummelled by the full force of Cyclone Ilsa may not be possible without outside help, its manager says as the clean-up continues.

The now-ex-tropical cyclone crossed Western Australia’s north-west coast as a category-five system on Thursday, bringing record winds of 213km/h and damaging isolated properties.

It has since tracked towards the southern Northern Territory, but is not expected to cause significant flooding.

Pardoo Roadhouse and Tavern, 150 kilometres north-east of Port Hedland, suffered at least $4 million in damage, with accommodation and staff rooms wiped out and the roadhouse roof ripped off, letting in torrential rain and debris.

“There is a possibility that we may not be able to rebuild,” manager Kelly Anne Martinez said in a Facebook post.

“We are not going to give up and we are exploring every possible avenue to fight for our roadhouse. But we need help.

“Everyone here … desperately needs action and support from the government.”

As well as tossing trees around the roadhouse grounds, Ilsa also dumped a road sign that had been stationed five kilometres down the highway, images posted to Facebook show.

While most staff waited out the storm from Port Hedland, a handful remained on site and rode it out in a shipping container.

Elsewhere, Telfer gold mine operator Newcrest Mining has begun assessing the Pilbara site for hazards such as fallen power lines and loose tree branches as well as any hidden structural damage.

WA Fire and Emergency Services Commissioner Darren Klemm said the full extent of the destruction could take days to assess.

In the Northern Territory, a severe weather warning for residents in southern regions was lifted on Sunday morning as the system weakened.

-AAP