Mitchell Avenue business Solid Engineering was assessing the aftermath on Thursday after the blaze broke through the back of the property and destroyed equipment and materials.

Solid Engineering director Trevor Reynolds said he realised the fire was getting serious around 2.30pm.

Mr Reynolds has worked in the Kurri Kurri area for about 18 years and said he has seen fires in the area before, but nothing as fierce as Wednesday’s.

“It had a fair bit of force in it, and it was blowing from all four directions,” he said.

“There were spot fires everywhere.

“But it sort of went past us, and then it came back.

“It all happened within minutes.”

Mr Reynolds said about $20,000 worth of property was damaged.

“But no-one got hurt, that’s the main thing,” he said.

He praised his staff for remaining calm under pressure.

“We ran some hoses out, there was no panic,” he said.

“One of the fire trucks got a flat tyre and some of our boys helped to change the tyre.”

Also on Mitchell Avenue, Kurri Used Building Supplies and Demolition was lucky to escape the brunt of the bushfire.

“We were very fortunate, the fire came up to the back of our property, it was pretty touch-and-go there,” shop assistant Tania Fenwick said.

“You didn’t know what it was going to do.

“It was so hot, so fast and so intense – it was pretty scary.”

The fire threatened homes on Northcote Street and falling embers caused damage to properties in Butler Parade and Kurri Kurri High School.

The Mitchell Avenue fire eventually joined up with a separate fire on McLeod Road (near Kurri Kurri TAFE), putting properties at Loxford, Heddon Greta and Sawyers Gully on high alert.

The fire had burned through more than 680 hectares of bushland by Thursday morning.

Police are investigating the cause of the fire, which is believed to have been deliberately lit.

Wednesday’s inferno was the third large bushfire in the Coalfields in as many months and one of a string of several outbreaks in the area this summer.

Bushfires wreaked terror on South Cessnock, Aberdare and Kearsley on the weekend of November 5 and 6, and Neath, Abermain and Weston on December 13 and 14.