Seta Tuiano said the family had earlier been celebrating her daughter's birthday on Saturday night; hours before the tragic accident.
"We just finished celebrating my daughter's third birthday dinner at James Cook Hotel with all my siblings - that was the last time we had our last dinner together."
She said three of her brothers, including Bah, had then planned to go to a friend's place for a kava session later that night.
They were on their way home when the accident happened.
Bah had not been driving, she said.
Their youngest brother, 23, was immediately taken to hospital in a critical condition. He continues to fight for his life.
Another brother, 33, is also in hospital. A third person - a cousin - also suffered minor injuries.
Two people from the ute suffered moderate to minor injuries.
The brothers do not know Bah has died.
"We just want them to recover fully and then be able to tell them,'' Seta Tuiano said through tears.
She described her brother as a dedicated son, partner to Aggie and friend and a loving father to his daughter Anne, 5, and 2-year-old son Bureta. He was also a keen league player; playing for a number of clubs over the years including the local Tongan and Tokelauan teams, Randwick and Petone Panthers.
"Everybody who knew him - he'd just meet someone and automatically they were brothers.
"He is an awesome father. He's the only one out of all my brothers that knows how to change a nappy properly. When I go somewhere, I leave my kids with him because he is such a pro. He's such a really good father, a playful father," she said.
"My brother lived by the motto: 'Live life to the fullest, but always trust in God and always have faith'."
