"Unfortunately their efforts were unsuccessful and the ambulance staff couldn't revive him," Mr Raynes said.
Last night, Mr Rimmer's family were gathered at his parents' house to support one another and to plan his funeral.
His sister, Jasmine Rimmer, broke the news on Facebook on Saturday, thanking everyone for their support.
"We have seen all the love and support and we appreciate it and thank you all so much ... We miss you brother."
Tributes to Mr Rimmer and messages of support from relatives and friends flooded his Facebook profile page.
His aunt, Deb Mayo, said she could not believe the "gutting news".
"You were such a go-getter and never let anything stand in the way of what you wanted to achieve. Just wrong you no longer wth us."
Ellie Sekar said Mr Rimmer was "an amazing and funny guy" who would be missed.
Mr Rimmer's funeral is to be held in Henderson on Wednesday.
A spokeswoman for the Department of Labour said it was investigating his death, but could not comment further.
In January 2009, Shane Darin Cockroft, 34, died when 1.5 tonnes of wet clay collapsed on him in a trench at a site in Nelson.
One month later, Mark Williams died in Te Kuiti when the side of a trench he was digging for a sewage line gave way and collapsed on top of him.