Pike River's long-awaited re-entry marks the start of the end of a journey for some of the families of men killed in the disaster.
The mine will finally be re-entered on Tuesday, weeks after it was delayed by faulty equipment and nearly a decade after the initial explosion.
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Twenty-nine men, ranging in age from 17 to 62, were killed after several explosions in the mine in November 2010.
It was New Zealand's worst mining disaster since 1914.
A loader will be brought into the mine on Tuesday to remove a concrete seal near the entrance, which will be witnessed by the families.
Spokesperson Sonya Rockhouse told The AM Show it will be a big moment.
"Pulling that plug out is like pulling the cork out of a bottle and releasing whatever... and it's just the beginning of the end of a journey for us."
Widow Anna Osborne told Newshub the families will take some time before the media arrive to take in the occasion.
They will meet at the mine at 10am.
"We really wanted it just to be about the families, just a couple of hours without being in the public eye I guess and the families really wanted it to be this way."
She said she's excited and nervous about the re-entry.
"I mean we thought it was all go on the third of May and unfortunately just a little tube bundling split in the pipe stopped the operation."
Rockhouse is hopeful further investigations into the mine could find evidence that could answer what caused the explosions inside the mine.
"There's an electrical... box, a memory card and a camera which will hold a lot of information about possibly what happened, but also there might be other bits of evidence, too, including possibly some body parts.
"It's one of those things we just don't know and that's the thing, there's 500 metres of the drift that hasn't been explored and so we need to go up there and see what's up there."