HAGERSVILLE, Ont. -- Provincial police say a man is in life-threatening condition after a large rock fell on him at a gypsum mine southwest of Hamilton.

The Ministry of Labour has been called in to investigate after the workplace accident at the Canadian Gypsum Corporation (CGC) facility in Hagersville, Ont. Thursday afternoon.

OPP say two men were working in an underground mine when a large slab of rock fell on them.

They say a 27-year-old man from Haldimand County was trapped underneath the rock and employees nearby had to work to free him.

Paramedics then rushed the man to an out-of-town hospital with life-threatening injuries.

Police say a 23-year-old man from Haldimand County who was also hit by the rock suffered non-life-threatening injuries and was taken to a local hospital.