Teenager fined for starting blaze with illegal fireworks in Sydney during bushfire crisis

A Sydney teenager has been fined $500 for setting off a round of illegal fireworks in a residential street during the summer bushfires.

The blaze in Guilford, in the city's west, came dangerously close to homes during catastrophic conditions on December 22.

Crews had to be called away from fighting blazes to deal with the fast-moving grassfire caused by the fireworks.

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Fadi Zraika was one of two then-18-year-olds, who was today sentenced for setting off explosives amid one of Australia's worst-ever bushfire seasons, during which 33 people were killed.

Magistrate Tim Keady paid tribute to the Rural Fire Service, whose resources were wasted fighting the fire.

"The air was filled with smoke, there was a large loss of property, huge areas burnt out, and deaths," he said.

"Throwing fireworks into a park was bound to cause a problem. It would have been obvious."

Police prosecutor Sergeant Rebekah Jung argued for "accountability", saying: "Members of the community were labouring terribly under these fires."

Rural Fire Service Deputy Commissioner Peter McKechnie warned people would be held responsible.

"People need to know, we're going to investigate those fires, we're going to work with the police, and we're going to hold people to account," he said.

When approached by a 9News reporter outside court, Zraika refused to answer questions.