Tokyo police will investigate the operator of a private sauna where a couple died on Dec. 15 inside a burning room after an employee said the alarm system had not worked for two years. 

Employees of the private sauna shop in Tokyo's Minato Ward told the Metropolitan Police Department that they had “not turned on the power for about two years” to the emergency button inside the room in question to the office.

The couple died in a fire at a private sauna after being apparently trapped inside and were unable to call for help. 

At around 12:25 p.m. on Dec. 15, an emergency call was made reporting that an alarm was sounding at a private sauna shop on the third floor of a building in the ward's Akasaka district.

According to the MPD, part of the walls in one of the private sauna rooms was charred. A man and a woman, believed to be customers, were found collapsed inside.

The deceased were identified as Masanari Matsuda, 36, a company manager, and his wife, Yoko Matsuda, 37, a nail artist.

The couple, who resided in Kawasaki, Kanagawa Prefecture, were pronounced dead at a local hospital.

According to investigative sources, there was an emergency button on the wall inside the room that, when pressed, would alert staffers to an abnormal situation. It was connected to the office on the first floor, where the power was managed.

After the fire, when the MPD asked the sauna shop’s owner and employees, they explained that “since around 2023, we have not turned on the power.”

The MPD believe that the practice of not turning on the power had become routine, and at the time of the fire, the emergency button was inoperable.

Police will investigate the sauna owner on suspicion of professional negligence resulting in death.

TRAPPED INSIDE

According to the Akasaka Police Station, the sauna room was about 2 to 3 tatami mats in size and contained a heating unit.

A bench and part of a wall—both made of wood and located away from the heating unit—were charred.

The couple had entered the sauna around 11 a.m. that day and had reserved it until about 1 p.m.

According to investigators, the incident occurred around noon that day, about an hour after they entered the room.

A smoke detector outside the sauna was activated, and an employee reported it to the fire department.

When they were discovered, the two were unclothed and were found collapsed on top of each other, with their heads toward the exit door.

The man had burns on both shoulders and other areas, and the woman suffered burns on her right shoulder and other areas, but these were reportedly not life-threatening.

Police will conduct an autopsy to determine the cause of death.

FATAL CHAIN OF EVENTS

According to investigators, when firefighters arrived, the doorknob for the private sauna's entrance was detached on both the inside and the outside and was lying on the floor.

The rod-shaped metal piece that connects the interior and exterior doorknobs was protruding outward, preventing the door from opening.

Firefighters had to push the metal piece back inside and turn it to open the door.

Inside the room, there was an emergency button connected to the front desk, and there were signs that it had been pressed.

The MPD believes the couple were trapped in the sauna.

The cause of the fire is unknown, but there was a heating unit inside the room.

It is possible that a towel burned first and then ignited multiple parts of the wooden bench and wall.

The MPD conducted an on-site inspection on Dec. 16.

In a key finding, investigators discovered that the power to the emergency alarm connecting the room in question to the front desk was off.

The control panel at the front desk is designed to centrally manage emergency buttons located in each private room, including the fire scene.

ESTABLISHMENT PASSED RECENT INSPECTION

The sauna is located about 300 meters south of Akasaka Station on the Tokyo Metro Chiyoda Line.

On its website, the establishment advertises itself as an "adult hideaway" and "completely private individual sauna."

It is described as having two single-person rooms and three four-person rooms.

On Dec. 15, a representative from the shop told The Asahi Shimbun, "We were open from the morning. The police and fire department are investigating the cause."

According to the Minato Public Health Center, the sauna had been in operation since July 2022.

The facility was inspected in April 2023 and the center said, “There were no major deficiencies found in the equipment."

(This article was compiled from reports written by Shomei Nagatsuma, Kaho Matsuda, Shun Yoshimura, Arata Mitsui and Hiroshi Nakano.)