A distracted aide at an Eden Prairie assisted-living center failed to plug in a resident’s heart pump at bedtime, and the man didn’t live through the night, according to a state investigation released Wednesday.

The state Health Department found the facility, Aging Joyfully, at fault in the July 10 death because it had no procedure to ensure the pump would keep operating when switched every night from batteries to electricity from an outlet.

Joy Hansen, owner and operator of the facility, a collection of nine private rooms located near the intersection of Pioneer Trail and Flying Cloud Drive, has complied with health officials’ orders for procedural changes related to the man’s death. Hansen said the primary change is that Aging Joyfully now has “some sort of documentation that residents are looked at every two hours” and a form to document the more frequent checks.

The resident was identified Wednesday by the Hennepin County medical examiner’s office as 79-year-old Bradley J. Mills, a father of four who lived in Burnsville and worked for the U.S. Postal Service for 36 years until he retired in 2000.

“It wasn’t good, was it?” said his wife, Kathleen, after reading over the findings. “I knew it was their mistake.”

Hansen sent her a card after Mills’ death, which said something to the effect of, “We’ll never really know what happened,” Kathleen Mills said.

Those responsible “will have to answer somewhere,” she added, “but to sue, what does it get you?”

The pump is known as a left ventricular assist device, or LVAD. It is implanted inside the patient’s chest to help a weakened heart pump blood. Without the device, Bradley Mills had only 10 percent heart function, the investigation revealed.

The device is the same type that has been keeping Minnesota Twins Hall of Fame infielder Rod Carew alive since it was implanted about 1½ years ago.

According to the Health Department investigation:

The caregiver was helping Mills into bed for the night when another resident wandered into the room. The aide directed the visitor out, but then forgot to plug Mills’ heart pump into an outlet for its nightly switch from batteries.

Another employee checked the room about 1 a.m. and saw that Mills was sleeping, but on the next check, at 5 a.m., saw that he had died and noted that the heart pump was not plugged in and “both batteries were depleted of charge.”

Hansen told investigators that her employees are trained on the heart pump’s operation and that its emergency alarm was given its daily test on the morning before the incident. However, she acknowledged, there was no procedure to record whenever the device is switched from one power source to another, and there was no requirement for overnight monitoring of the pump’s operation.

The medical examiner’s report noted that the device alarm did go off about 1:30 a.m. to warn of a low battery, but no staff recalled hearing it. Hansen said the two overnight staffers who didn’t hear the alarm no longer work at the for-profit facility; one left voluntarily and the other was fired, she said.