The VA Medical Center in Tomah, Wisconsin is accused of over-prescribing opiates and retaliating against employees who objected.
On Monday, U.S. Secretary of Veterans Affairs Robert McDonald announced that his agency will investigate the allegations, starting this week. The review is expected to take at least a month.
A former Marine died of an overdose in the hospital, last summer.
Over the weekend, Senator Tammy Baldwin took responsibility for not pursuing reports of wrongdoing at the Tomah VA sooner. She indicated that a constituent brought issues to her attention last March, and that a 2014 investigation fell short of exposing problems at the medical center.
Last week, Baldwin asked the VA Secretary to launch a new investigation, and he promised it would begin this week.