Firefighters have collected more than 1,000 presents for needy children this Christmas, after a charity's stockpile was destroyed when the Little Saigon Market at Footscray went up in flames.

The offices of the Les Twentyman Foundation, which had collected presents and textbooks for disadvantaged children, were destroyed in the fire.

United Firefighters Union (UFU) Secretary Peter Marshall said the firefighters who tried to put out the fire were behind the push to replace the presents.

"They actually reflected on the tragedy, and how the kids were going to miss out, and spontaneously they started to organise, [asking] 'what can we do?'" he said.

"So they started to organise a fundraiser [and] many of the presents they bought themselves."

UFU firefighters collected more than a thousand presents for disadvantaged children this Christmas. ( ABC News: Stephanie Anderson )

Youth charity founder Les Twentyman said he was overwhelmed by the response.

"It's been quite traumatic at times, but also it's become quite uplifting, the amount of support that I've got from the Victorian public," he said.

"These kids barely get to smile because of the problems of poverty and particularly generations of unemployment.

"This is generally the only day — Christmas Day — that they have something to be happy about, and that almost went."

Mr Twentyman said he did not want to think about what would have happened if the unions and the public had not stepped in to help.

He said the presents would go to about 500 families on Christmas morning, while a $14,000 donation would go towards the children's school costs.

Unexpected arrival for a family devastated by fire

Les Twentyman accepts a delivery of presents for disadvantaged children from Santa. ( ABC News: Stephanie Anderson )

After finishing the delivery, the firefighters made an unexpected stop nearby.

Fire gutted a house in Sunshine in the early hours of Thursday morning, and the family was lucky to escape unhurt.

Peter McMahon, 13, had a visit from Santa, to try to spread some Christmas cheer.

His father, James, said he thought a burglar was breaking into the house when he heard glass cracking during the fire.

"I went out to the back step and found there was just flames engulfing up the back step there," he said.

"So I ran in and got rid of the family, told them to get out of bed, the next thing I came in and gee, it just took over."

The family did not have a smoke alarm, and will be staying in emergency accommodation over Christmas.