Bernie Monk lost his son Michael in the Pike River Mine disaster.
A 25-year-old woman killed in a crash in Nelson was Kelsie Monk, the niece of Pike River spokesman Bernie Monk.
Kelsie Linda Monk died following the crash in Stoke on Thursday night, shortly after midnight.
Speaking to the Herald this morning Bernie Monk, confirmed his niece had been a passenger in the car.
"We're absolutely devastated," he said.
"Our families are very, very close."
Bernie Monk said it was an emotional time, and the family was hoping for privacy to allow them to get through it.
Monk lost his son Michael in the Pike River Mine disaster in 2010. He has been a tireless spokesman on behalf of the families who lost loved ones in the mine.
Three other people were taken to Nelson Hospital with serious injuries following yesterday's crash, which happened on Whakatu Drive in Stoke.
Kelsie Monk was one of three passengers who were thrown from the vehicle after it lost control, left the road and rolled.
Shortly after the incident, Fire and Emergency shift manager Andrew Norris said one person was trapped in the car. Firefighters had to pull them out.
Those injured were aged from their mid-20s to 30s.
Inspector Paul Borrell said the vehicle was travelling from Nelson in the direction of Richmond.
"This crash is a tragedy for the friends and family of the woman killed and those injured, as well as the wider community," he said.
The crash was one of two fatal incidents on our roads on Thursday night.
One person died shortly after midnight after a car hit a power pole in the Auckland suburb of Green Bay. A second person suffered critical injuries and is now in a stable condition in hospital.
And two others died in Northland yesterday in two separate crashes.
A man died after a motor scooter crash in Northland yesterday evening. A police spokesperson said a man in his 30s died in the crash on Whakapara Rd in Russell, about 5.45pm.
About 4pm a person died in Whareora, Northland, after apparently falling from a vehicle.
The protest will pass over the harbour bridge this morning.