The man was buried by earth after a wall that was built specifically to prevent soil from sliding gave way.
"At the arrival of the firefighters and Urgences Santé paramedics, he was still conscious," said Urgences Santé Chief of Operations Marc-André Gagnon.
Gagnon said the man was still conscious, though he had suffered serious injuries to his upper and lower extremities.
He was transported to a nearby hospital, where he was pronounced dead.
Quebec's workplace health and safety board is on site investigating the incident.