Police continue to investigate leads from the public after five fires were deliberately lit around Yallingup on February 6, 2021.
At a community meeting on Saturday authorities detailed the action taken to extinguish the blazes by emergency services and volunteer firefighters.
A 000 call at 6.26pm alerted authorities to the first fire near Duckworth Place in Naturaliste. A second 000 call at 6.42pm reported a fire near Hemsley Road.
At 7pm a third 000 call reported a fire at Injidup, and at 7.23pm an additional two fires were discovered there.
Within half an hour of the first fire being reported an emergency warning was issued for the Yallingup townsite and later Injidup as reports of multiple fires were called in and intelligence from the ground.
A telephone warning system was also issued to residents living in the Injidup area alerting them to the emergency unfolding.
City of Busselton community emergency services manager Blake Moore said in less than an hour from the first 000 call they had five fires.
Mr Moore said the local volunteers who helped fight the bushfires were nothing short of extraordinary.
"The level of response the brigades gave was amazing, to manage five fires at once was a great effort," he said.
"We were quite stretched in the initial stages but the effort and how they pulled together was amazing."
South-West District Superintendent Geoff Stewart said anyone with any information regarding the fire should contact Crimestoppers on 1800 333 000 or make a report online at crimestopperswa.com.au.
Mr Stewart said they had received information from the public and would still like people to contact Crimestoppers with any information they may hear from friends in the community.
Rewards of up to $50,000 are offered for reporting information that leads to the identification and conviction of arsonists.