More than $60,000 in donations have flooded in for the family who lost two children in a devastating house fire overnight.

The fire in the Christchurch suburb of Burwood claimed the lives of 8-year-old Brayden and his baby sister Arianna.

There had been several children in the Vivian St home when it burst into flames.

Father, Des, heroically saved the lives of two of the other young children.

He was injured when he re-entered the burning house to try to save Brayden and Arianna.

Brayden was rescued by firefighters during search and rescue operations, but died later.

Arianna, who was only 9 months old, was found dead in what an emergency service official described as an "unsurvivable bedroom".

Emergency services at the scene last night. Photo / Chris Lynch

Ashley Looyer has established the Givealittle page to support the family.

"Your donations will help the family of Brayden and Arianna cover funeral costs and help them get back on their feet without the financial burden that will accompany this horrific loss," the page reads.

By 8pm, $54,183 had been donated by more than 1000 donors.

Many people expressed their condolences on the page, leaving messages of sympathy and love.

One donor said: "No parent should have to endure that horror."

Another said they were "sending strength and love".

NZ Gift of Love and Strength a Christchurch-based charity is taking donations for the family, which can be dropped of at the local Little Explorers Preschool.