A 65-year old man and a 58-year old woman died Sunday after using a decompression chamber at a hot springs in Saitama Prefecture.
According to the Saitama Prefectural Police, the two people from the city of Fujimi were not breathing when found in the chamber and were confirmed dead at a hospital later that evening.
The air pressure in the dome-shaped chamber, which is about 2 meters high and 3 meters deep, had been artificially reduced to a level equal to an altitude of some 3,500 meters.
A worker at the facility, Manainoyu, in the city of Fujimino, called for an ambulance at around 5:30 p.m. Sunday, saying there were customers who apparently were not breathing.
On its website, Manainoyu touts the chamber as a place to improve health and prevent the contraction of diseases. The police are investigating the business and how it operates the room, suspecting that either an accident occurred or the victims had health problems.