A 49-year-old Margate man who was working at the site died at the scene.
Two other workers were also injured, including a 43-year-old who was flown to the Rockhampton Hospital with a broken leg.
The other, a 41-year-old man, suffered minor injuries and was transported by road to the same hospital.
The Capricorn Highway was closed for about two hours after the incident and the forensic crash unit are continuing to investigate the tragedy.
More to come