THE deadliest bushfires recorded in Western Australia have claimed at least four lives and burnt through more than 200,000 hectares of prime agricultural country.
A lightening storm at the weekend sparked about a dozen fires across the south-west of the state near Esperance.
Two men and two women are confirmed dead. One of the dead men is local farmer, Kym Curnow, who was earlier warning neighbours to evacuate.
There were also fears for the lives of two other people in the region on Wednesday.
The raging inferno is the deadliest on record and comes eight years after three men died in the Boorabbin bushfires after being allowed through a roadblock.
The fires have ripped through crops, which are being harvested. Farmers had only harvested about a third of their crops before the fires hit.
It is estimated between 200,000 and 300,000 tonnes could have been lost. Based on current prices, the value of the crop losses could be between $58 million and $87 million.
The crops provided a large fuel load for the fires.
"The losses are going to be quite horrific," said WA Farmers president Dale Park.
"There will be farms that will still have buildings but there's a lot of the crop that hasn't yet be harvested. There will be [sheep and cattle] stock losses.
"We heard one of the fires travelled 60 kilometres [on Tuesday]. Imagine trying to get stock out in front of that."
WA Farmers estimated over 130,000 hectares and 15,000 sheep had been destroyed.
Grains handler CBH Group closed its Esperance grain terminal and shut six grain storage sites.
Farmers in the region were forecast to harvest about 2.7 million tonnes this year, or about 20 per cent of the state's forecast 13 million tonne crop.
The state's biggest farmer, John Nicoletti, has farms in the region but they have not been damaged by the fires.
"No one really knows how much has been lost [in the region] because they can't get in there. But it could be 200,000 to 300,000 tonnes. It's absolutely devastating," Mr Nicoletti said.
"But we are not worried about the grain. We are worried about people's lives," he said.
Premier Colin Barnett said he was devastated by the loss of four lives and flew to Esperance on Wednesday.
Mr Barnett tweeted: "My thoughts & prayers with families whose loved ones have died in the Esperance fires. Gratitude extended to all emergency service workers."
Prime Minister Malcolm Turnbull tweeted: "Lucy and I join all Australians in expressing our love & solidarity for the families who lost loved ones in the terrible fires at Esperance."
Esperance shire president Victoria Brown told the ABC the remote coastal community was in shock after "the day from hell".
"It was devastating," she said.
"They got many of the fires out, but there were a few still burning and they combined into an inferno."
While some of fires have been extinguished, two major blazes were burning on Wednesday at Grass Patch and Salmon Gums, 100 kilometres north of Esperance, and at Stockyard Creek, 25 kilometres east of the town.
Mr Park said farmers in the region had been looking forward to the rewards of a particularly good season.
"Esperance was the poster boy for us this season," Mr Park said.
"It is a high-producing area. Where you might be getting one to two tonne per hectare [of grain] the Esperance area is more like four to five tonnes per hectare."
Nearly 500 people were without power in the region. Several hundred people have been evacuated.
Department of Fire and Emergency Services Commissioner Wayne Gregson described the fire conditions on Wednesday as "catastrophic and unstoppable".
Cooler conditions were expected to aid firefighters on Wednesday and Thursday but hot weather is expected on Friday, Saturday and Sunday.