t was the start of night shift when the tunnel began filling with gas.Workers going underground at the Snowy 2.0 site say they were told that there was nothing to worry about, that it was just water vapour.
But on that Saturday in early July, chemistry had finally caught up with them.
The previous year, the giant machine digging tunnels for the project had caused a sinkhole to open up.
Workers had spent seven months trying to stabilise the nearby ground, pumping in thousands of litres of grout, cement and polyurethane foam.
Now that foam had triggered a chemical reaction, producing toxic gas.
Snowy Hydro, owned by the federal government, has never disclosed this safety breach, even as it pumps out highly produced videos and press releases.
It was not meant to be this hard.
The pumped hydro project, trumpeted as a grand "nation-building" scheme, was first estimated to cost just $2 billion. It's blown out to $12 billion.
It was expected to produce its first power next year — now, it won't be keeping any lights on for at least another four years.
Snowy Hydro has revealed to Four Corners as much as $2 billion of this blowout can be blamed on the stalled tunnel boring machine they call Florence.
Its 15km journey below Kosciuszko National Park should be well underway by now, but it's gone just 150m.Insiders say warnings were ignored — Florence was doomed from the start.
