Two construction sites on the Vancouver waterfront were shut down Thursday morning after a worker was killed and another seriously injured in separate accidents just minutes apart.

Just before 8 a.m., a man fell a reported 90 feet while he was working on the sails above the northeast portion of Canada Place. The sub-contractor was rushed to hospital.

Mike Shardlow, CEO of Canada Place, said the man suffered life-threatening injuries.

Minutes later at a construction site just a block away another man was fatally injured.

A 28-year-old worker was killed after being hit by a wooden form that came loose at the Harbour Green condo construction site in the 1100-block of Cordova Street.

Both sites are run by Ledcor construction, but it is not believed there are any connections between the jobs. The company hasn't had a fatal accident in five years.

Ledcor shut down four major projects in the downtown core while investigators tried to determine what went wrong.

"Once details of the investigation are known, Ledcor will be carrying out a stand-down of its Vancouver construction projects to share relevant information with all work crews and to reinforce with its sub-contractors Ledcor's strong commitment to safety," said Lee Coonfer, vice-president of communications.

Representatives from WorkSafe BC are also investigating. Spokeswoman Donna Freeman said the accidents are unprecedented.

"In my experience this has never happened -- two incidents in such close physical proximity and so close in time. It's tragic."

There is an average of 10 construction industry fatalities a year in British Columbia. Falls and people struck by objects are the two top causes of death in the construction industry.

The B.C. Federation of Labour places the blame on employers and a lack of government regulation.

"We have to get tough with employers and make sure there's some punishment when workers die. Because it's not going to stop until we get tough," federation president Jim Sinclair said.

"It keeps happening over and over and over."

With reports from CTV British Columbia's Peter Grainger and Norma Reid