A crane operator was killed Monday when his machine tipped over onto its side at a construction site in Maplewood.

The accident took place at noon outside the St. Paul Hmong Alliance Church, 1770 McMenemy St., according to Maplewood police. The church is reportedly building an addition.

According to police, Cory Lewellin was operating the crane at the worksite when the machine toppled. The 34-year from Ogilvie, Minn., in Kanabec County north of the Twin Cities, was trapped inside the cab, which became at least partly submerged in soft soil at the worksite.

Other construction workers were digging out the cab when rescuers arrived. Once extricated, Lewellin was taken by ambulance to Regions Hospital in St. Paul, where he was pronounced dead.

His family could not be reached for comment Monday.

Assistant Maplewood Police Chief Dave Kvam said soil conditions following excavation might have been a factor in the accident. The crane's hydraulic outriggers, which stabilize the machine, were set, but they might have sunk into the soft soil, Kvam said.

Witnesses said the crane, which is mounted on a wheeled chassis, was moving what appeared to be a beam when the machine fell over. Its boom crushed a fence on the north side of the property and partly extended into a residential yard. No one else was injured.

The Minnesota Occupational Safety and Health Administration is investigating.

"It's an open investigation, and we are reviewing the details of what may have caused or contributed to the accident," said James Honerman, a spokesman for Minnesota OSHA.

Lewellin's crane is owned by Truck Crane Service of Eagan.

A message left for the company's president, Paul Doran, was not returned Monday.

The company has had no accidents reported to OSHA in at least the last five years, according to OSHA records.

Sixty Minnesota workers were fatally injured on the job in 2011, according to a Minnesota Workplace Safety Report compiled by the MN Department of Labor and Industry and published this year. In 2010, 70 fatal injuries on the job were recorded in the state.

The construction industry was noted as having the highest rate of accidents, the report said.

Sarah Horner can be reached at 651-228-5539. Follow her at twitter.com/hornsarah.