His 34-year-old brother Daniel Kopa, who was hit by a car while crossing the road in Auckland, died after his life support was turned off on Thursday afternoon.
Chris, who lives on Australia's Gold Coast, told the Herald he had just woken up when he learnedof his brother's death.
"I got a call from his wife Calli... I knew something was wrong by the way she sounded. I knew what had happened."
She was "trying to hold it in and keep her composure," Chris said.
Dann's brothers liked to tease him because "he was such a hard man as a young guy", but his daughters had softened him, in a good way.
Chris said his brother had a bike when his daughter Harper was younger, and he put a seat on the back so he could take her for rides.
Turning off Dann's life support was difficult, Chris said. Dann held his daughters in his arms while it was turned off.
"I've got a two-year-old, and it was his birthday the day we turned off his life support... But he understands and wanted to be there for him, everything just happened so quick."
Calli was heartbroken, but she was surrounded by loving family, he added.
Dann Kopa's best friend Jonny Chambers, 34, said Dann was "just an amazing dad", always there for his family and friends.
The pair met at Papakura High School and were best men at each other's weddings.
"He always strived to improve himself, and was constantly trying to advance himself."
Dann and Calli's children were lovely natured, he said: "You get that when you have such a devoted dad."
Chambers said he wanted to express their gratitude for all the support the family had received.
"There were people camped in corridor at the hospital, and the staff tolerated that for over three days. It was hundreds of people coming through, and I know that must not have been easy."
Dann had been brought home from hospital yesterday evening to his family house in Pukekohe, Chambers said.
A Givealittle page set up for the family has received more than $105,000 in donations.
"We're just trying to express our thanks to the public, some of the messages of support are just heart wrenching."
Dann will be lying in state at the Papakura Marae from 1pm Monday 12 until Wednesday morning, Chambers said.