VANCOUVER - British Columbia Premier John Horgan says he was shocked to learn that no provincial charges will be laid in the 2014 collapse of the tailings dam at the Mount Polley mine.

The disaster at the gold and copper mine was one of the largest in the province's history and sent 24 million cubic metres of mine waste and sludge into nearby waterways.

A three-year deadline on charges came Friday amid an ongoing investigation by B.C.'s Conservation Officer Service, but earlier this week the agency's deputy chief Chris Doyle couldn't say what stage the probe was at.

Horgan said he remembers seeing the devastation firsthand in 2014 and to have three years pass without any consequences is disturbing for him personally as well as for all British Columbians.

However, he said the federal government is very much engaged in the investigation and the province will work with federal investigators to ensure there are consequences for the events that took place.

Horgan, who was sworn in last month, said the Conservation Officer Service is limited in its resources and his government will get to the bottom of why more resources weren't deployed.