Pilot Thomas Menzies could be forgiven for thinking World War Three had started when he took this photo from a helicopter.
But, thankfully, this wasn't the mushroom cloud of an atomic bomb.
A NSW Rural Fire Service spokesman confirmed the smoke had created what's known as a "pyrocumulus cloud" or "fire cloud".
It was formed during a 100-hectare hazard reduction burn in Worimi Conservation Lands at Fern Bay on Thursday.
"Light winds in that area meant the column was more spectacular than you'd normally see if wind was pushing the smoke away," the RFS spokesman said.
The NSW Office of Environment and Heritage said the burn was done to "provide protection to homes and properties from bushfire".
"Mild autumn conditions provided an ideal opportunity to carry out the hazard reduction burn, scheduled as part of a strategic fuel reduction program for the area," a spokesman said.
More burns are planned next week, if conditions allow.