Sydney mourns young life lost in Barcelona terror attack

Tributes have poured in for the Sydney schoolbooy tragically killed in Friday's terror attack in Barcelona, as his young classmates try and comprehend what happened.

Julian Cadman was killed and his mother was seriously injured when a van ploughed into crowds in the Spanish city's busy Las Ramblas district on Thursday.

As world leaders and local politicians took to Twitter to share their condolences, one heartbroken mother stood outside St Bernadette's Catholic Primary in Lalor Park in disbelief as to how the seven-year-old's life was so cut so short.

“We saw him every day with his grandmother at the bus stop,” Karuna Nicodemus told the Blacktown Advocate.

“The children are really upset because it’s very sudden news. They play together ... it’s such a devastating experience, such a lovely boy."

Sydney schoolboy Julian Cadman was killed in the Barcelona terror attack. Photo: 7 News

Blacktown mayor Stephen Bali said the entire community was hurting as a result of the seven-year-old's death.

"Julian, you were a much loved member of our local community whose life was tragically cut short, may you rest in peace," he wrote on Facebook.

Julian's rugby team, the Giraween Eagles, also offered condolences.

"Please remember children can react in a range of ways to grief and take note of advice from schools and counsellors on ways to discuss this sad news," the club posted on its Facebook page.

"Julian was a delightful little boy - curious and energetic with a kind and generous heart," Catholic Education Diocese executive director Greg Whitby added.

"He was much-loved by his teachers and fellow students."

Australian schoolboy Julian Cadman was visiting the city with his mother. Picture: Supplied

Meanwhile teachers at Julian's primary school have had to share the heartbreaking news of his death with his "devastated" classmates.

The children at St Bernadette's Catholic Primary in Lalor Park are now being offered counselling.

"They have been provided with some expert advice around that, and the counsellors are in classrooms and supporting staff during the course of the day," Mark Rix from the Catholic Education Office said.

"We invited parents to stay back after the morning assembly and those counsellors have been moving through that group as well and providing some support for the parents as well."

In a heartbreaking statement, Julian's family said they were so blessed to have had him in their lives.

“Julian was a much loved and adored member of our family. As he was enjoying the sights of Barcelona with his mother, Julian was sadly taken from us,” they said in a statement.

“He was so energetic, funny and cheeky, always bringing a smile to our faces. We are so blessed to have had him in our lives and will remember his smiles and hold his memory dear to our hearts."

A Go Fund Me page has been set up to help with medical and funeral costs for the Cadman family.

"Andrew, Jom and Julian are a normal Aussie family whose lives have been devastated by the recent tragedy in Barcelona," the Go Fund Me page reads.

"Like all families they are are paying a mortgage, bills and other sundries.

"As you can imagine there will be ongoing medical costs to get Jom back to full health.

"We are asking for any contribution for those that may wish to help."

The page has already raised $31,000 in the three hours since it was launched.

Contributions to the Julian & Jom Cadman Go Fund Me campaign can be made here.