But still none of those in charge has been held accountable.
Now a team is slowly making its way down the 2.3km entry tunnel in the search of evidence that might lead to a prosecution, and, although the chances are slim, the bodies of the men inside.
Today, 114 families and friends will make the trip back up to the portal of the mine, deep inside the Paparoa Ranges.
The ongoing recovery effort will be paused and at 3.44pm, the time of the first explosion, there will be a minute of silence, followed by a roll call, where the names of the men will be yelled down into the mine.
Bernie Monk, who will shout out the name of his boy Michael, has been at the forefront of trying to get back in there.
"There was quite a few years there, we weren't even allowed to go to the portal and then we finally got our way. And now there's a lot of family members that have actually walked down into the mine. So, you know, slowly, we're getting there."
Despite the Minister Responsible for Pike River Re-entry Andrew Little saying it was too risky to go beyond the rockfall, where the men most likely were, Monk was not ready to give up hope of one day being able to give his son a proper burial.
"People have said that we're never going to go through the rockfall but you know, there's still a chance that could happen. I mean, they've made these calls outside the mine and all the experienced miners that I've talked to both here and overseas, say to me, Bernie you can't judge a rock fall until you're actually standing in front of it."
Cloe Nieper lost her husband Kane in the mine.
She will not be making the trip to the portal, preferring instead to visit the memorial at Atarau, at the turn off to Pike River.
She has had to raise their son, Kalani, by herself for the past 10 years, and said it did not feel like a decade had already gone by.
Kalani was just 19 months old when Kane died.
"Kalani's been my rock so he's actually kept me going to be honest with you. I don't know where I'd be without him to be honest, he's definitely my medicine and he makes me get on with it and do what I have to do. I'm very, very lucky I've got him."
After visiting the memorial today, Cloe and Kalani will head to their own special place to remember Kane.
"We're lucky enough that the boys at the Kahuna Boardriders Club, they made a seat for Kane and Glen Cruse, where Kane and Glen used to surf, so we've got a seat there that we go to and that's where we do our little thing."
Members of the public wanting to mark the day will be able to join in a service at Blackball at the Museum of Working Class History, where a number of family members will also gather.
There will also be an official event at Parliament involving other family members, the prime minister and the husband of the late Helen Kelly, who joined in the fight to see somebody held accountable for what happened at Pike River.
Sonya Rockhouse, who will attend the event at Parliament alongside her friend Anna Osborne, told Morning Report: "Sometimes it feels like a lifetime and other times it just feels like it was yesterday."
Sometimes she feels distressed because she can hardly hear the sound of her late son Ben's voice.
Her other son, Daniel, who survived the disaster is working in the mines in Australia and will commemorate the day with some other workers from Pike who are in Queensland.
He has been unable to return home because of the Covid-19 pandemic.
"It's very sad that he's not going to be here because even though he survived he often says that he wishes it was him down there and that Ben had survived...
"My heart broke for him. He's affected forever."
Osborne, whose husband Milton died in the explosion, said she missed him hugely especially as she has been in poor health.
"It's still very raw for me but we've actually now got a beautiful little granddaughter who's nearly three and she's the apple of my eye. She's filled a bit of a void that I had in my life and I just love her to bits."
Both women resent that they never heard from the company about the explosion.
"To this day we're still waiting to be told officially which is really poor and one of the things we'd like to change. I just don't know how they can do that."
A lot of work still to be done
Osborne said there remains a lot to do around workplace safety. Laws needed to be strengthened to provide safer working environments. Since Pike 700 people had been killed in workplace accidents - the equivalent of a Pike River every five months which was "absolutely appalling".
Legislation also needed to be enforced.
"We need employers to be held to account. We need a day in court for a lot of people. It seems like you can go to jail for killing a cat but no employer has ever been to jail for killing a worker. That shows you how weak our laws are," Osborne said.
Rockhouse said the families had been deceived after the disaster.
"What they should have done was told us the truth. They should have been truthful with us from the beginning. We might not have liked it but we would have eventually accepted it."
It was important how families were treated after a tragedy because they were the collateral damage.
"We felt like over and over and over we were being traumatised by all the lies and deceit that was happening. We don't want to see other families having to suffer and fight the way we've had to so that's one thing that needs to change along with the health and safety laws which should work hand and hand really."