Three residents died after a carbon monoxide leak at St. Mary's Villa, a special care home in Humboldt, in 2010. (City of Humboldt)

The Saskatoon Regional Health Authority was fined $154,000 after a carbon monoxide leak at a Humboldt seniors home killed three residents in 2010.

In addition to the deaths, seven workers and 24 seniors got sick at St. Mary's Villa, a special care home, after carbon monoxide backed up from the boiler and entered the ventilation system.

Yesterday, the health region pleaded guilty to two Occupational Health and Safety charges relating to not protecting workers and not inspecting the boiler.

Mitch Miller, the crown prosecutor on the case, said that mechanical problems and lack of thorough inspections over the years allowed the carbon monoxide to enter the facility.

The charges only relate to the health region employees, Miller said.

"With respect to the illnesses and the deaths, there are other mechanisms that can deal with that, such as the coroner's inquest and I guess from a legal standpoint that's where it is," he said.

The coroner's inquest is still in the the planning stages.