A small rural primary school at Cowwarr, north of Traralgon, has been destroyed by fire overnight, after the first day back to school.

Twenty-two children, including three new prep students, are enrolled at the school and had their first day of classes yesterday.

The fire started around 9:30pm and took an hour to control.

The school burned down after the first day back for students. ( Supplied: Sandra Shumski )

More than 60 firefighters from surrounding towns were called to fight the fire but they were unable to save the main school building.

School principal Albie Fitt said the entire town was devastated.

"We were all there last night, all gathered around together, consoling each other because in a small country school people are connected," Mr Fitt said.

"So we were just looking at it and thinking this is just so sad.

"We had three new preps, we all started yesterday and we were looking forward to a fantastic year."

Parent and firefighter 'kinda broke down a little bit'

Mick Cachia has three children at Cowwarr Primary School and is a member of the Cowwarr Country Fire Authority that was first on the scene.

"The school has done a lot for my kids. I did have four kids there, and one has moved on to high school," he said.

"I hope it gets rebuilt. The community is pretty strong, and the school means a lot."

Mr Cachia said it was difficult to a fight a fire at his children's school.

"When I came off the fireground I kinda broke down a little bit, but I tried staying strong because I knew I had a job to do," he said.

Principal Albie Fitt says the town is devastated by the fire. ( Supplied: Sandra Shumski )

'Like an extension of your home' says principal

Mr Fitt said Cowwarr was "a great little school".

"We don't have children away from school because they want to be there," he said.

"We had an assembly yesterday that was filled with parents and we were all excited together as the school year started.

"I am really concerned about the children because of their close connection to the school because the ones that have heard are very upset."

Mr Fitt said staff had also lost personal belongings in the fire.

"I lost a 12-string guitar I bought in 1977 that was my pride and joy and that was burnt in the fire," he said.

"Because it's a small school, the school is like an extension of your home, you're there at weekends sometimes."

The Victorian Education Department is making alternative arrangements for the students, and police and fire investigators are determining the cause of the fire.