A 64-year-old American woman has reportedly become the first person to die using the Sarco suicide pod, according to its creators.

The assisted suicide occurred near a woodland cabin at Merishausen, Switzerland, as confirmed by the Swiss firm behind the device, the Last Resort, the Daily Mail reports.

Police in northern Switzerland detained several people on Monday and have opened an investigation on suspicion of incitement and accessory to suicide. The Sarco capsule is designed to allow the occupant to press a button to inject nitrogen gas into the sealed chamber, leading to death by suffocation within minutes.

“The device performed exactly as it had been designed to do,” the inventor of the capsule, Philip Nitschke, said, noting that it provided “a non-drug, peaceful death at the time of the person’s choosing,” .

The deceased woman reportedly had been suffering from a severe illness that involved significant pain and had expressed a desire to die for at least two years.

“The woman had been suffering for many years from a number of serious problems associated with severe immune compromise,” the organization said. A co-president of the Last Resort, Florian Willet, was the only person present at the time of death.

Following the suicide, police, including forensic teams, arrived at the scene after being notified by a legal firm. The Sarco capsule was seized, and several people in the Merishausen area were taken into custody.

A Dutch newspaper, Volkskrant, reported that one of its photographers was detained by police while attempting to take photos of the event. The police confirmed that the photographer was being held at a local station but did not provide further details.