YPSILANTI (WWJ) - A 37-year-old inmate died suddenly at Michigan's only women's prison after complaining about a bee sting last week.

Chris Gautz, Public Information Officer for the Michigan Department of Corrections, an investigation is ongoing into the death of Lisa Marie Johnston, who was serving time for delivery of methamphetamines at the Huron Valley Correctional Facility in Ypsilanti when she said she was stung, and apparently suffered a severe allergic reaction.

Johnston was taken to St. Joseph hospital and kept for two days, Gautz said. After the woman's release on Friday, Gautz said Johnson had been back at the prison for only about two hours when she collapsed and died.

Gautz noted that Johnston was supposed to get a prison health exam, but skipped out on it.

"As is routine when a prisoner comes back from a hospital they're scheduled to see our nursing staff at the prison. She had an appointment set up for that," Gautz told WWJ's Sandra McNeill. "She went to the nursing area, but she left on her own before being seen by our health care staff."

Gautz said Johnston left the waiting area to push a fellow inmate in a wheelchair to get in line to receive insulin. After that, Gautz said, Johnston wheeled her friend to the cafeteria.

"While she was pushing the prisoner in the wheelchair between the health care unit and the chow hall she began to complain of feeling dizzy to the prisoner she was pushing, and then she collapsed."

Gautz said it took the private ambulance company 30 minutes to arrive, but it appears Johnson had died immediately.

They're awaiting a Medical Examiner's report to confirm if it was, in fact, a bee sting that killed the inmate.

"When we're hearing right now is that the autopsy is still considered pending. The pathologist wanted to confer with a cardiologist before making a final determination, as I understand it," Gautz said. "I believe there are some other medical issues at play."

Will there be any changes made at the prison as a result of Johnston's death?

"We really need to know what happened to her specifically. If this was just a medical condition that she had, there's really...nothing that we can change on our end," Gautz said. "We've not had any issues with bees that we're aware of at the facility...There's not like an infestation of bees or anything like that that we need to be wary of. It could've just been a fluke thing."

It's even possible that perhaps there was no bee sting, Gautz said, and that Johnston suffered a reaction to something else.

Michigan State Police, corrections officials and health care staff are investigating.

Johnston's family has been notified.