State regulators said Monday they are investigating the death of a worker who fell to his death at a soon-to-be-closed biomass plant in central Minnesota that supplies power to Xcel Energy.

The man fell into a hopper at the Benson Power plant in Benson on Wednesday, according to Minnesota's Occupational Safety and Health Administration (OSHA).

Rescue personnel arrived that afternoon, and "lifesaving measures were administered on scene," police said in a statement.

The man was transported to a nearby hospital and "did not survive his injuries," the statement continued.

Authorities have yet to disclose his identity.

OSHA has investigated what also is known as Fibrominn twice since 2012 and fined the operation both times, once for $1,050 after a safety inspection detected inadequate hazardous energy controls.

The other investigation led to an $8,400 fine for violations involving flammable and combustible liquids and wiring, methods, components, and equipment; and $2,800 for failure to properly inform employees about training requirements and provide access to work-related written material.

For the previous five years, workplace fatalities involving falls in Minnesota average five per year, according to Minnesota OSHA. That type of deadly incident is second in the state to contact with an object or equipment, averaging eight a year for the previous five years.

On Nov. 30, state utility regulators approved Xcel's plan to close the 55-megawatt Benson plant and two other biomass electricity generators. The move will save ratepayers money but will also lead to economic distress for the timber and turkey farming industries.

Xcel plans to buy the Benson plant, which has been in operation since 2007 burning turkey manure mixed with wood chips to produce electricity, before closing it. Xcel said the buyout will lead to long-term savings of $345 million.

Paul Walsh • 612-673-4482