The president of PCL Construction, Ian Johnston, told CBC News the man was working to build scaffolding at Agrium's Vanscoy potash mine when he fell from the platform 18 metres off the ground between 3 and 3:30 a.m. CST.
"There were people in the area and very immediately people knew and there was radios and they put a call out," said Johnston, who was on his way to the mine site. "We have on-site EMTs and they responded within minutes… and he was pronounced dead right at the time."
Johnston said there is no immediate information about what led to the man's death, which is the eighth fatality at the mine.
RCMP and Occupational Health and Safety officials are investigating.
"We're very concerned and we need to find out exactly why it happened and understand what we can to do to make sure it doesn't happen again," said Johnston.
Johnston said the man is from Newfoundland and his family has been contacted, but his name is not being released at this time.
PCL sent their workers home for the day after the accident and Johnston said grief counsellors will be provided for anyone who asks. Most of Agrium's employees were sent home as well.
The mine is Agrium's only potash production facility and is in the midst of a $1.5 billion expansion that is expected to raise capacity by 50 per cent, or one million tonnes. Construction began in 2012.
It's located about seven kilometres west of Vanscoy, a community 25 kilometres southwest of Saskatoon.