A correctional officer at the Fort Saskatchewan Correctional Centre died Thursday from COVID-19.
A message posted by his family on Facebook, identifies the officer as Roger Maxwell.
The notice adds, "During his brief illness Roger expressed his concern that his colleagues could contract COVID-19."
The Alberta Union of Provincial Employees said they believe Maxwell was in his 50s.
The news has upset staff at the provincially-run jail, said Susan Slade, AUPE vice-president.
"I actually talked to the chapter chair this morning," Slade told CBC News. "It's very devastating and everybody is very upset and obviously very sad about this situation."
Alberta Health Services said 37 inmates and nine staff at the jail have tested positive.
"It's just a scary place to be on the front lines in those facilities," Slade said. "We're begging people to follow the rules. Wear a mask.
"Keep yourself safe so that these members that go in every day to these facilities are also being kept safe when they're outside of the facility they're working in."
Slade said the union will investigate to determine whether Maxwell contracted the virus on the job.
In it's Facebook post, Maxwell's family asked staff at the facility to thoroughly disinfect desks, phones, phones and workstations "to prevent the loss of another officer."
An Occupational Health and Safety review will be initiated, said a spokesperson with the department of the Solicitor General which governs provincial correctional facilities.
"Our thoughts and prayers are with the family and loved ones at this very tough time, along with those who worked with the officer," Katherine Thompson said in an email to CBC News.
"With the pandemic, their work, as with other frontline professionals, has become even more challenging. They continue to meet this challenge head-on."
Outbreaks have also been declared at the province's two large remand centres. Currently there are 198 inmates, 35 staff and one contractor who have tested positive at the Calgary Remand Centre.
There are 41 inmates, 16 staff and one contracted staff member who have COVID-19 at the Edmonton Remand Centre.