Four staff members at an Oklahoma VA hospital have resigned after a 73-year-old veteran receiving treatment died, according to Fox News and other outlets.

Myles Deering, executive director of the Oklahoma Department of Veterans Affairs, has attributed the veteran’s death to sepsis, a life-threatening complication of an infection. He says the maggots did not cause Peterson's infection.

Four staffers at the hospital have been named in the investigation. All four, including the hospital’s director of nursing, quit before they could be investigated or terminated.

The case has been referred to the Oklahoma State Department of Health and the District Attorney’s Office for LeFlore and Latimer counties to determine if cause exists to file criminal charges.

It's another mark against the Oklahoma Department of Veteran's Affairs. In 2012, a caretaker pleaded guilty to misdemeanor charges stemming from time at the Claremore Veteran's Administration Hospital.