A Columbia Heights company that removes weeds from lakes has been hit with the state's largest-ever work safety penalty — $730,369 — after one of its divers died after working underwater.

Joseph Anderson, 18, died in May after an accident on Lac Lavon Lake in Apple Valley, where he was cleaning out weeds for Your Lake Aquatic Plant Management.

Minnesota work safety regulators tagged the company in November with five "willful" violations of commercial diving standards. Willful violations are rare and reserved for the most egregious worker safety infractions.

An investigation by the Minnesota Occupational Safety and Health Administration found Your Lake employees didn't have the experience or training to perform work safely, nor were they instructed in first aid and CPR.

Your Lake had not developed a safe-practices manual, and did not have an employee in charge of diving operations on the day Anderson died, according to Minnesota OSHA.

Your Lake Aquatic Plant Management is contesting the citations. Grant Johnson, a co-owner of the company, declined to comment Tuesday.

Anderson was one of six Your Lake workers cleaning out weeds 10 to 15 feet below the surface of Lac Lavon Lake on May 21. After several minutes, Your Lake workers realized they hadn't seen bubbles coming up from Anderson, according to the OSHA investigation.

Anderson's co-workers found him unresponsive and without a mouth device that delivers air from a scuba tank.

The job was Anderson's first time diving with scuba equipment, the investigation found. He had received only 10 to 15 minutes of training from a co-worker who wasn't scuba certified, OSHA concluded.

Anderson had planned to study business entrepreneurship this fall at Grand Canyon University in Arizona, according to his obituary. He had already earned two years of college credits at Bethel University while he was still in high school.

Three of the Your Lake's allegedly "willful" safety violations in connection with Anderson's death were each for $161,323 — the maximum allowed. The other two each tallied $123,200.

OSHA issues willful safety citations only when companies know a hazardous condition exists, but don't make reasonable efforts to eliminate it.

Anderson is the second Minnesota worker in two years who has died while scuba diving to remove underwater weeds. An employee of Wayzata-based Dive Guys drowned in June 2022 while working in Lake Minnetonka.

OSHA hit Dive Guys with three serious safety citations totaling $26,950 and two willful violations, each for $50,000. Dive Guys contested the case and OSHA knocked down the fines for the two willful citations to $29,539 each, OSHA records indicate. The serious citations were reduced to total of $15,920 in the settlement.

The fine against Your Lake is the second particularly large penalty levied by Minnesota OSHA this year.

Wayne Transports, a Rosemount-based trucking company, was hit in July with $621,000 in fines, which at the time was the largest-ever safety penalty recorded in Minnesota. OSHA cited Wayne for 12 serious safety violations in connection with a worker's death at its Virginia, Minn., terminal in March.

An Iron, Minn., man was found dead in the tank of a tanker truck, likely succumbing to asphyxia and chemical exposure, according to a coroner's report.

The large penalties against Wayne Transports and Your Lake came after a 2023 state law that increased fines for work safety violations. The maximum willful penalty before the law was $70,000 — about $90,000 less than the current fine. States fines were increased to conform with federal OSHA penalties.

The third- and fourth-largest penalties ever levied by Minnesota OSHA involved also willful citations.

Minnesota OSHA tagged Meadowlands Farmers Coop in Lamberton with six willful violations for a total of $375,000 in 2018 after a worker died from suffocation in a grain silo. Meadowlands contested the case and settled for $232,000 in fines.

Gateway Building Systems, a construction company, was tagged with six willful citations for $323,000 in 2017 after a worker fell from a platform while working atop a grain elevator. Gateway also contested and settled for penalties of $143,000.