A 76-year-old woman who was declared dead at a hospital in Ecuador shocked her relatives by knocking on her coffin during her wake-keep, prompting a government investigation into the hospital.

Retired nurse Bella Montoya was admitted to hospital on Friday, after suffering a possible stroke and cardiopulmonary arrest. When she did not respond to resuscitation a doctor on duty declared her dead, Ecuador’s health ministry said.

Barbera said his mother was unconscious when she was brought to the emergency room and that a few hours later a doctor informed him she was dead and handed over identity documents and a death certificate

The family then brought her to a funeral home and were holding a wake for her later on Friday, June 9 when they started to hear strange sounds.

“There were about 20 of us there,” Barbera said. “After about five hours of the wake, the coffin started to make sounds. My mom was wrapped in sheets and hitting the coffin, and when we approached we could see that she was breathing heavily.”

“It gave us all a fright,” son Gilberto Barbera told the Associated Press, adding that doctors said his mother’s situation remained dire.

Relatives rushed Montoya back to the hospital in the central city of Babahoyo, Barbera said, where the health minister said she was in intensive care. She was under intubation and doctors weren’t giving relatives much hope about her prognosis, Barbera said.

The ministry said it was investigating the doctors involved in her case, and a technical committee had been formed to review how the hospital issues death certificates.