SHE was a celebrated employee, the most senior and experienced female operator at BMA's Caval Ridge Mine.
But just two years after she was invited to meet then Prime Minister Tony Abbott at the mine's opening, she was sacked after not disclosing she drove a dozer through a zone potentially filled with explosives - although she said she had told her employers.
Now, Sarah Engel has had her unfair dismissal claim rejected by the Fair Work Commission.
Commissioner Jennifer Hunt, in her decision released on January 5, wrote that from the evidence given at the hearing, before Ms Engel's night shift on February 10, 2016 Ms Engel was told about an exclusion area at the mine due to an explosive misfire.
The misfire happened that day, after the drill and blast department had filled holes in the ground with explosives, detonators and boosters. One of these columns didn't fire. That area had been zoned off with cones 10m around the hole.
During that night the experienced operator, working for her contractors Central Queensland Services, was rotating between the dozer and shovel with another worker cutting through a big wall.
GPS information from the dozer showed the other worker had "dug a significant way through the exclusion zone, through the misfire itself, and then through to the outer side of the exclusion zone".
Later in the shift Ms Engel, as proven by GPS from the dozer when she was driving it, "entered the misfire exclusion zone" three times, twice getting within 6.5m and once within 10m of the misfire.
It was later shown to the Commission the explosives had been removed earlier that day but neither worker or their supervisor knew that.
In her evidence to Commissioner Hunt, Ms Engels stated she saw the exclusion cones placed to help workers identify the area but because the other worker had knocked over the front cones she thought the remaining cones were the start of the zone, not the end.
An investigation took place into the other worker driving into the zone. The supervisor and other worker were stood down on February 15 and March 15, 2016 respectively.
The Commissioner found that at this stage Ms Engel hadn't told the investigator she had driven into the zone and she knew the other worker had told the supervisor about incident.
In Ms Engel's evidence, she stated that when the investigator met with her to give her a final warning she said "the investigation had clearly failed".
"All the information must not have been collected otherwise I would not be receiving a first and final warning," her evidence read. "I alerted to (the other worker) that he had dug through the misfire, and that he had to report it to (the supervisor) and he told me he was doing so."
The Commissioner's decision found that CQS human relations manager "considered Ms Engel's actions in failing to report the incident unacceptable" and she "lost confidence in Ms Engel's ability to perform her role safely, and she did not hold any confidence ... should Ms Engel perform work at the mine" and Ms Engel was fired on April 15, 2016.
Ms Engel challenged her right to respond to the allegations before being fired but Commissioner Hunt found "I have had regard for the procedural fairness deficiencies above, and I am satisfied having determined that Ms Engel engaged in the conduct resulting in her dismissal, that despite the procedural fairness deficiencies, Ms Engel's conduct was of sufficient gravity to justify termination of her employment."
"I find that there was a valid reason for the dismissal."