TORONTO -- Ontario's New Democrats demanded to know Wednesday why six of nine charges were dropped against mining giant Vale Canada Ltd. in connection with the deaths of two workers in a Sudbury mine.

An inquest into the deaths of Jordan Fram and Jason Chenier at Vale's Stobie Mine in June 2011, which was set to begin next month, was called off after the company agreed to pay a $1-million fine in exchange for reduced charges.

The community waited a full year before the Ministry of Labour laid charges, only to see two thirds of them dropped just before the inquest, where people would have heard just what went wrong, said Sudbury New Democrat France Gelinas.

"It was to be our day in court. That process had been expected by my community for a long time, and then a couple weeks before they come out with a fine," said Gelinas.

"We will never know exactly what was found, why were those charges laid in the first place, but the question that everybody has is who agreed to this plea bargain and who agreed to withdraw those charges."

Premier Kathleen Wynne told the legislature she didn't have all the details of the plea bargain, but said more details of what caused the accident will come out in coroner's inquests.

"What I do know is that coroner's inquests are automatic for all mining and construction fatalities, so there will also be a coroner's inquest into these fatalities so that more answers will be available," said Wynne. "I think those are the kinds of reviews that need to happen."

But Gelinas said there had been "hundreds" of coroner's inquests over the past 30 years into fatal industrial accidents, but miners continue to die on the job in Ontario.

"There are issues with safety in our mines that must be addressed," she said.

The $1-million fine against Vale is the highest ever levied in Ontario for violations of the Occupational Health and Safety Act, added Wynne.

The nickel mining giant pleaded guilty to three charges related to mine safety and was fined $350,000 for each count for a total fine of more than $1 million, plus a 25 per cent victim surcharge.

The two men died from "massive crushing injuries and multiple blunt force trauma" from an uncontrolled run of muck, a combination of broken rock and ore, 900 metres underground.

The Ministry of Labour said its investigation revealed that Vale Canada Ltd. -- a wholly owned subsidiary of the Brazilian mining company Vale -- failed to deal with water issues, leading to the deadly accumulation of wet muck clogging the mine.

The United Steelworkers International union said the deaths of Chenier and Fram could have been avoided if Vale had not ignored ongoing problems with flooding in the mine.

Gelinas said people in the northern community need more answers about the tragedy and the plea deal to drop most of the charges against Vale.

"The plea bargain, maybe it was the right thing, maybe it isn't, but it was all done behind closed doors," she said. "So for a community that has been waiting to gain closure, we know those men, we know those families, people are grieving. People are suspicious and they think the worst."