ST. PETER — Construction crews are finishing a $56 million expansion to the Minnesota Security Hospital in St. Peter aimed at improving safety, but a union official said even more needs to be done.

The hospital treats people civilly committed by state courts as mentally ill and dangerous. The addition’s modern design is much safer for staff and patients, according to the Department of Human Services.

Hospital director Carol Olson said it will be easier for staff to monitor patients, and that smaller units will make it harder for patients to hurt themselves.

“If someone is focused on trying to harm themselves, when you have them on a unit with 15 to 20 other people, it’s hard to prevent what their peers are giving to them that they could use to harm themselves,” she said. “When you’re on a unit with just two people you can control that a lot more.”

Safety conditions are improving slowly, but workers still aren’t getting all the training they need, and they’re too often subject to mandatory extra shifts, said Tim Headlee, president of the union that represents hospital staff.

“We have the data, we have the documentation from other facilities that we’re not within the proper patient-staff ratios,” Headlee told Minnesota Public Radio (http://bit.ly/2ea6CaH ).

Even with the new building and its 104 beds, half the hospital remains in the old facility built in 1982, with its blind corners and poor sightlines.

Human Services Commissioner Emily Piper said Gov. Mark Dayton plans to ask lawmakers to authorize millions more dollars for new construction and more workers.

“Last year, he sought over $20 million to increase staff at Security Hospital and the Legislature didn’t fund any of that request, so he will be bringing that additional staffing request back to the Legislature as part of his budget this coming year as well,” she said.

Patients are expected to move into the expansion in January.