One worker fell 30 feet through a skylight. Five workers were caught in moving equipment. Three were pinned under equipment or material.

In all, 31 Minnesota workplaces were cited in the 12 months ending in June for violations that contributed to serious on-the-job injuries, according to investigative reports and citations issued by the Minnesota Occupational Safety and Health Administration.

Following are the 10 companies with the highest negotiated fines:

Grain Commerce Inc., Amboy, $30,480 fine

An employee was using an auger to move corn from one grain bin to another. The worker grabbed some corn for sampling. Something hit and pulled the worker's hand into the auger.

The company was cited for failing to provide a guard for moving parts, failing to train employees on safe practices and failing to make sure an auger was de-energized when a worker entered the bin. Grain Commerce also had no written accident-reduction program in place, failed to make sure the air in a bin was safe to breathe and willfully failed to provide a bin worker with safety evacuation equipment and a designated observer.

VZ Hogs LLP, Claremont, $18,150 fine

An employee was attempting to clear a jam in a compactor that crushes containers of expired milk and juice in order to extract the liquid for use as hog feed. Not realizing the first employee was there, another employee turned the machine on, which caused a hydraulic ram to pin the first employee in the machine's extruder. VZ Hogs failed to train employees on how to clear a jam safely, make sure employees are clear of the machine before starting it and de-energize the machine before performing maintenance.

Metal Sales Manufacturing Corp., Rogers, $10,500 fine

A hydraulic-press brake operator was making a part when the machine unexpectedly cycled, causing a ram to close on both of the worker's hands. The worker was able to use the foot switch to raise the ram.

The company was cited for a repeat violation for failing to have a protective device or guard on the machine. Its accident-reduction program was also out of date.

Pace Industries, Maple Lake, $10,150 fine

While attempting to fit a die-cast machine with a reusable steel mold, an employee's right hand was crushed between the mold and its housing. Pace failed to cut electrical power to machines during maintenance and failed to properly train employees to do so.

Mesabi Bituminous Inc., Gilbert, $7,425 fine

An employee climbed to a platform in preparation for repairing a piece of equipment that hadn't yet been shut off. After flipping up a guard to expose the machine's motor, the worker slipped and fell. The worker's hand and arm were caught in the pinch-point between a sprocket and chain. Mesabi did not have a written accident-reduction program in place, failed to have a guardrail on a raised platform, failed to have procedures in place or train employees to de-energize equipment before performing maintenance and it allowed moving parts to be exposed.

Stocker Excavating Inc., Lakeville, $7,318 fine

The operator of an excavator was using its bucket to move standing water in a trench to a different area. Another worker was directing the operator when the second worker was struck by the bucket. Stocker failed to provide a workplace free of recognizable serious hazards, failed to have proper cave-in protection (a repeat violation), provided a ladder that was too short and failed to provide adequate safety training.

Rayco Construction Inc., Minneapolis, $6,000 fine

A worker scraping roofing material off a 30-foot-tall warehouse fell through a debris-covered skylight and "glanced" off a 20-foot-tall stack of paper rolls before dropping to the floor. Rayco was cited for failing to conduct regular safety inspections of the roof while it was being worked on, failed to provide guardrails or personal fall-arrest equipment or implement a training program.

Jones Metal Products Inc., Mankato, $5,800 fine

Employees were moving a 1,600-pound piece of sheet metal. When a worker temporarily unclamped the piece from a crane, the worker holding the piece in a vertical position lost balance. The sheet fell on the worker's legs. Jones failed to provide a workplace free of recognizable serious safety hazards and failed to inspect a hoist regularly.

Dietz Brothers Inc., Rochester, $5,750 fine

Employees were working on the ground assembling a section of a wind turbine tower when the section rolled, pinning two employees. Dietz failed to provide a workplace free of recognizable serious safety hazards and keep workers clear of suspended loads. The company did not have a written accident-reduction program in place.

Express Employment Professionals, East Grand Forks, $5,250 fine

A temporary worker received a shock when the worker picked up a damaged 480-volt power cord lying on a concrete floor. The cord had recently been driven over by a truck filled with sugar beets and, following a popping noise, the machine powered by the cord had shut down. Express Employment did not protect the power cord or require the employee to inspect the cord prior to starting his or her shift.

Hard Data digs into public records and puts a spotlight on rule breakers in Minnesota. Contact me at jfriedmann@startribune.com.