A union boss claims concerns about work practices were raised with safety authorities at Mechanical Vegetation Solutions long before a young worker tragically lost his life this week in a workplace accident.

The Timber, Furnishing & Textiles Union (TFTU) SA chapter secretary Dave Kirner said they first raised alarm bells over Mechanical Vegetation Solutions in April, directly warning regulators that workers had a number of concerns.

“We actually emailed Mechanical Vegetation Solutions – and we let SafeWork SA know – that these sites had problems with letting people work alone with dangerous equipment,” Mr Kirner said.

“And these are big issues – working alone – because if something happens there’s no one there to protect you or notify others.”

Labourer Josh Thomson-Parkin, 26, was killed on Tuesday after heavy machinery he was operating fell on top of him.

Emails sighted by The Advertiser confirm the union urged SafeWork SA to inspect the company’s operations four months prior to the fatality.

“Can an inspection be done of safe work practices at Mechanised (sic) Vegetation Solutions 4 Takisman Court, Edwardstown,” an email sent by Mr Kirner on April 21 read.

In the wake of the incident, Mr Kirner met with the “shaken” workers on site who said they felt unable to raise safety concerns with the company.

SafeWork SA is investigating the fatality. With Mr Thomson-Parkin’s grieving family and union representatives demanding answers from Mechanical Vegetation Solutions over why the young worker was left unsupervised in such high-risk conditions.

The SafeWork SA spokesman also said inspectors had identified noncompliance with health and safety laws, consequently issuing two Prohibition Notices to stop certain activities from occurring across the company’s worksites.

“The scene has been preserved while investigations continue,” the spokesman added.

“(And) the company’s previous compliance history and any earlier interactions with SafeWork SA will form part of the investigation.”

Mr Thomson-Parkin had been operating heavy machinery alone on Tuesday at a Charleston worksite, when the accident occurred.

When he failed to return home, his father Max drove through the Wednesday morning fog just before 6am to search for him. That’s when the desperate father made the heartbreaking discovery at the worksite.

A Mechanical Vegetation Solutions spokesperson said they were “deeply saddened by the death of our valued team member” and they extended “sincere condolences to Josh’s family, friends and loved ones”.

They added they were “co-operating fully with SafeWork SA and the relevant authorities as they investigate the circumstances surrounding the incident”.

A group of Mr Thomson-Parkin’s family and friends, including wife Mekayla, gathered at the Aldinga Hotel to celebrate his life on Friday night.