Police confirmed Monday that an explosive called ammonium nitrate was found in the gas tank of a contractor’s bulldozer at Vale’s Coleman mine in September.
In late September, Vale contacted police about an act of mischief after a bulldozer was inoperable.
“When they started looking at why the bulldozer stopped working, they found something had been poured into the gas line in the bulldozer,” Sgt. Rick Waugh said.
After investigating, tests show the substance is ammonium nitrate, an explosive “commonly used” in the mining industry, Waugh said.
Vale spokeswoman Angie Robson said the company is helping police with the investigation.
Waugh and Robson wouldn’t speculate on a possible motive, but a nearly year-long strike of more than 3,000 steelworkers at Vale’s Sudbury operations ended in July. Many Steelworkers were angry that some contractors helped Vale operate during the labour dispute.
Ammonium nitrate is a white crystalline solid at room temperature and standard pressure. It is commonly used in agriculture as a high-nitrogen fertilizer, and it has also been used as an oxidizing agent in explosives.
Ammonium-nitrate-based explosives were used in the Oklahoma City bombing that killed 168 people on April 19, 1995. Timothy McVeigh, an American militia movement sympathizer, detonated an explosive-filled truck parked in front of the Alfred P. Murrah Federal Building downtown.