The Occupational Safety and Health Administration is expected to continue its investigation of an accident that claimed the life of a Marietta man last week at a local water plant.

According to authorities, 56-year-old John Henry Brown of Marietta died about 1:45 p.m. Thursday after being trapped under heavy equipment at the Forsyth County Water Treatment Plant off Antioch Road.

“He was not operating any machinery,” said Karleen Chalker, spokeswoman for the Forsyth County Sheriff’s Office. “He was standing beside some machinery that was operational and it overturned on him.”

Sheriff’s Capt. Frank Huggins said the agency has concluded its investigation of the incident and does not suspect foul play.

“As far as we are concerned, it was an industrial accident,” Huggins said.

OSHA will return to the site Monday.

Forsyth County Fire Capt. Jason Shivers said it is not clear how Brown became trapped under the heavy machine, which he described as similar to a forklift.

“It did roll over and he was trapped beneath it,” Shivers said. “Unfortunately, he passed away and we could not save him.”

No other injuries were reported in the incident.

Shivers said Brown, a subcontractor who was not a county employee, was working in an area where the plant is being expanded.

In a statement released Friday, the Forsyth County government expressed its condolences about the incident.

“Forsyth County is saddened by this tragic accident and loss,” the statement said. “We extend our sincerest sympathy to the victim’s family, friends and co-workers.”

Jodi Gardner, county spokeswoman, said the project will expand the water plant’s capacity to treat an additional 12 million gallons per day. It is expected to be complete by the end of 2011.