GILLAM, Man. -- An employee with Edmonton-based contractor that's building a transmission line for Manitoba Hydro's Keeyask generating station is dead after a job-site accident.

The contractor, Forbes Brothers Ltd., said the man was critically injured while securing a load on a semi-trailer truck early Wednesday at a construction materials marshalling yard about 45 kilometres from Gillam.

Corey Papp, Forbes' vice-president of corporate services, said the labourer was with three fellow employees when something came off the load and struck him on the head.

He said the man was conscious while he was being taken to hospital in Gillam, where he was to be stabilized before being airlifted to Winnipeg.

"He was talking to the paramedics that transported him but he became worse once he got into the hospital."

The 22-year-old worker, who was from Lake Manitoba First Nation, had been with the company since 2015. His family has been notified, but his name was not immediately available.

No one else was injured.

Scott Powell, a Hydro spokesman, said two employees of the Crown utility were also there when the accident happened and helped with the first aid.

Papp said the worker would have been trained to carry out the job he was doing.

"Our belief is accidents just don't happen. There's always causes to accidents and that's what our investigation is uncovering," he said. "We're going to be looking at all training records, competency evaluation forms, making sure the individuals doing the work were competent and skilled to perform their work."

The marshalling yard has been shut down while representatives from Manitoba Workplace Safety and Health investigate. Papp noted that all the company's work sites in the province have also been closed in the interim.

Kelvin Shepherd, Hydro's president and CEO, said in a statement that the Crown company's condolences go out to the worker's family.

"This is a very sad and tragic incident," said Shepherd. "Counselling has been made available to all contractor and Manitoba Hydro employees who were on site at the time of the accident."

This is the second time in recent months that Forbes Bros., has been hit by a fatal accident.

Papp said two company workers were killed near Come By Chance, N.L., last year while erecting a transmission tower for Newfoundland and Labrador Hydro. One of the employees was from Ontario while the second person was from Saskatchewan.

"It was unrelated to this incident but it was certainly very sad. We investigated with the authorities at that location and took action to correct issues that led to those deaths," he said.

The Forbes website says the company, which was incorporated in 1977, has grown to become one of North America's largest privately held utility construction contractors. The site states it is "North America's most practical, respected and reliable utility constructor."

The northern Manitoba line Forbes is building will carry power from Keeyask to the existing Radisson converter station just outside Gillam.