After 10 grim days for the Germanwings search team, Alice Coldefy -- the only woman working at the crash site -- found the elusive black box on her first day on the job.
"Everyone was happy. It was a relief... a relief for all the people that had been working there for a week-and-a-half without a break," the 32-year-old told AFP.
Coldefy is the only woman in the 43-strong team of elite mountain police (PGHM) charged with recovering the body parts from the plane wreckage.
On Thursday, she was for the first time assigned to work on the crash site, scouring for clothes and personal effects with another officer.
"I was really concentrating on personal effects. We were trying to get into areas that hadn't yet been searched to find as many clothes as we could," she told AFP.
"And it was while I was looking for clothes that I found it," she said.
Blackened from the fireball and shaped a bit like an oversized shoe-box, it was especially difficult to spot as it was the same colour as the surrounding rock.
"We had a photo of the black box from various angles. We got it out, compared it to what we had found and it was indeed that," she said.
It was a key moment in the investigation.
The precious find was rushed to Paris immediately where experts were able to analyse the flight data.
The data showed that the pilot in the cockpit, 27-year-old Andreas Lubitz, deliberately set the autopilot to smash into the mountains and even adjusted the speed manually to accelerate the crash.
- 'Hard to breathe' -
Coldefy described the near-impossible working conditions for rescuers scrabbling into the mountain scree for debris and clues.
Even for an experienced mountain climber like her, well used to clambering up the peaks of Mont Blanc -- Europe's highest mountain -- this search presented particular challenges.
"Physically, the hardest thing was all the dust that we kick up. We're working with masks on but even then it's hard to breathe. We need to use ropes in the steepest areas," she said.
The black box with its hundreds of potentially vital clues was at the "end of a very steep ravine" under a pile of debris.
Jean-Baptiste Estachy, commander of the mountain police unit from nearby Chamonix, said he was "very happy with Alice's work."
"She's a very discreet person who does not try and put herself out there," he said.
In 2012, Coldefy was the first woman to join the elite mountain police force in Chamonix. Of the 15 PGHM units in France, there are only three female officers.
In September, she also became a mountain guide, joining the 30 or so women in this profession of some 1,600 people.
"What a relief," she sighed, describing her emotions when she first caught sight of the hidden box.