More than 4,600 U.S. workers were killed on the job and an estimated 50,000 died from occupational diseases during 2012, a new report from the AFL-CIO labor federation found.

The federation’s annual report, Death on the Job, analyzes the most recent data on workplace deaths and injuries available from the federal Bureau of Labor Statistics. The report released Thursday noted that the death rate among U.S. workers has trended downward long-term, though that progress has recently ebbed.

“Over the years, clearly the United States has made progress in protecting workers,” said Peg Seminario, director of safety and health at the AFL-CIO, on a call with reporters Thursday. “But today the numbers of workers being killed and injured is still too high and unacceptable. Over the last several years, the rate for injuries and illnesses has essentially flatlined.”

In the AFL-CIO’s analysis, North Dakota was by far the country’s deadliest state to be working in, with 17.7 workers killed per 100,000. That’s compared to a national rate of 3.4 deaths per 100,000. North Dakota was followed by Wyoming, at 12.2 deaths per 100,000, and Alaska, at 8.9 deaths per 100,000.