Fifty-two years on, the Brynderwyn bus crash, as it became known as, is the subject of a episode in the TVNZ series Descent from Disaster which will air tonight.
"It was just an ordinary sort of day and then someone said a bus had gone off the Brynderwyns and that's all we knew," Mr Spiers said.
He grabbed his boss's car and then Advocate cub reporter Kevin Ball and rushed to the scene.
The bus was carrying mainly Aucklanders, many of whom were related. They were travelling home from Waitangi Day celebrations.
On the south side of the hill the bus's brakes had failed causing it to crash over the side of a cliff. Fourteen people died on impact while another died later that day.
Mr Spiers declined to be interviewed for the documentary but Mr Ball, two survivors, two siblings of those killed and the son of the bus driver were interviewed.
Mr Sainsbury said he hoped the documentary had helped them get closure.
Producer Ross Peebles said outside of Northland many people still did not know about the crash.
"We want people to remember history because it's important and to learn from it. People will see it's a very emotionally charged story."
-The Descent from Disaster episode featuring the Brynderwyn Bus Crash will screen tonight, at 8.30pm on TV One.