BALINGUP and Bridgetown residents described the smoke cloud rising from last week's fires as looking like "an atom bomb".
The fires started on Tuesday last week as a result of lightning strikes in bushland between Balingup, Greenbushes, Bridget own and Nannup.
One major ignition point was west of the Blackwood River in Southampton, where flames crossed the river and burned through almost 4,000ha of bushland, plantations and farmland.
Two houses were destroyed, including the historic Southampton Homestead, dating from 1862.
Southampton Bridge was also destroyed.
Greenbushes residents were evacuated, and Balingup and Bridgetown residents put on a watch and act alert on Wednesday night.
Balingup and Greenbushes schools were closed on Thursday.
The fires were contained by Friday and all warnings downgraded to bushfire alerts.
More than 200 personnel from the Department of Environment and Conservation, the Department of Fire and Emergency Services, the Forest Products Commission and local volunteer Bush Fire Brigades continued to fight the fires over the weekend.
Labor candidate and Bridgetown local John Thorpe was in Boyup Brook on Wednesday when he saw what he described as a mushroom cloud of smoke going straight up in the air before he headed for home.
"It was quite worrying, the closer you got the more smoke there was," he said.
He watched the smoke cloud approaching his property until the wind changed and turned it away.
"We were extremely lucky," he said.
Balingup resident Mike Armstrong saw the smoke from the Balingup main street.
"It looked like an atom bomb," he said.