According to Roseanne Burns, one of Casey's close friends, Barnes was packing freshly-shorn fleeces to make more room in the wool pack.
It is believed a piece of Casey's hair became caught in the electric motor above her head. The belt-driven motor drives a shaft which runs the shearers' shears.
As the motor caught her hair, and tightened it’s grip, Casey’s scalp came with it, ripping away from the back of her head and above her eyes and ears.
With her boyfriend and brother close by, Casey was flown to Sydney by emergency services for emergency surgery in an attempt to save her scalp.
Casey was placed in an induced coma, with the hope that the limited head movement would help the healing process.
Doctors would then attempt more surgery - but unfortunately, Casey's scalp could not be saved.
Now, Casey has to pin her hopes on surgery to attach artificial skin to her scalp instead.
The whole experience has put a massive financial strain on the rural NSW family.
Desperate to help, Roseanne — the sister of Casey’s boyfriend Boyd — established a GoFundMe page.
The page reads, 'Our darling Casey, who is such an incredible fighter, has a long road to recovery and will be based in Sydney for some time.
'Both Casey and my brother are from country towns hours from Sydney. As a shearer and a roustabout, not only is it bloody hard work, but if it rains you don’t get paid.
'There is no such thing as annual or sick leave in the industry, you don’t work you don’t get paid.'
The post finished, 'The money will be used [for] 'accommodation, food and travel expenses' while family are needing to be based at Sydney to be with our beautiful, brave, happy-go-lucky-giggle Casey.'
To help with Casey's recovery, please see her GoFundMe page.
This article originally appeared on New Idea.
Have you heard our gripping new podcast How I Survived? Listen below to hear incredible mum Michelle Dowsett describe how she was scalped at 13 weeks pregnant!