The Department of Veterans Affairs is investigating less medical errors even through harmful accidents are occurring more frequently than ever.

In a recent report from the Government Accountability Office, the VA investigated 18 percent less of its own screw ups between 2010 and 2014. When the GAO questioned VA officials, they admitted that they haven’t even investigated why they aren’t investigating as many medical errors. In the meantime, medical mistakes have increased by seven percent.

A medical error caused by the negligence of hospital staff can mean the difference between life and death. For example, Marine Jason Simcakoski died on Aug. 30, 2014 because VA doctors prescribed him to many sedative medications. When Simcakoski was found unresponsive in his hospital bed due to his meds, hospital staff were so inept that they could not even find his heartbeat or take his pulse. Their inability to resuscitate the patient cost the Marine his life.

Simcakoski’s story is only one example of how medical errors can harm a patient. Between 2010 and 2014, more than 500 military veterans died in VA hospitals due to mistakes, ranging from a failure to sterilize surgical equipment to accidentally placing feeding tubes in a patient’s lungs.

Investigating why a medical error occurred helps hospitals prevent that error from happening again. If a VA hospital doesn’t bother to review high-risk errors, it can’t prepare its staffers for similar situations and save other veterans from being harmed.