Details were not clear, but David Parker, director of communications and sustainability for the mining giant, confirmed the dead included a Teck employee, an outside consultant contracted to work on the Sullivan mine's decommissioning and two ambulance paramedics who responded to the initial call for help.
Susan Dolinski, an emergency services spokeswoman, said she had no details except that an paramedic team had responded to a call from the mine.
Kimberley Mayor Jim Ogilvie told Canadian Television News that something happened with a pumping station that transfers acid water either into or out of the mine.
"I understand that there is someone who was in a very serious situation and three other people went to help him and they as a result of doing so are in serious difficulty," Ogilvie said.
The lead-zinc mine closed on Dec. 21, 2001, after 92 years of production.
After the closure, Teck Cominco began extensive decommissioning and reclamation. The decommissioning process was to end this year and involved four Teck employees and several contractors.
The work included reclaiming disturbed lands, an extensive assessment of the mine site's risk to human health and the environment, contaminated site assessments and demolition of unused buildings and other structures, Teck said.