CBH has moved to shut its WA grain storage, rail and port network after a 69-year-old contractor died while carrying out maintenance work at Northhampton.
CBH said the site was shut down immediately and a decision had been made to close the entire network.
"Closure will happen over the next few hours, with the network fully shut down by 4pm today until 6am tomorrow morning," the grain co-operative said.
"CBH wants to take time to allow employees and contractors the opportunity to absorb this information and to refocus on safety."
CBH described the fatality as a tragedy and said its thoughts were with the family and friends of those involved.
"CBH representatives are liaising with the local authorities and the Coroner's office to provide the appropriate support," it said
The co-operative said it could not comment further on the incident as police and WorkSafe were investigating.