The death of a British tourist at a hospital in southern Greece is under investigation after the man collapsed while accompanying his wife for medical treatment, authorities said Thursday.

The 55-year-old man was vacationing in the Kalavryta area with his wife when she fell ill on Wednesday. He took her to the local hospital, where doctors and nurses provided medical care. As her condition was improving, the man reportedly collapsed unexpectedly at her bedside.

Medical staff tried to resuscitate him but were unable to save his life.

The cause of death has not been determined, prompting a post-mortem examination to be ordered, while police in Kalavryta conduct a preliminary investigation into the incident.