Police on Tuesday searched the offices of the operator of Tokyo’s Roppongi Hills commercial complex, where a 6-year-old boy died last week after his head was crushed by an automatic revolving door, as well as the distributor of the door system.
Investigators searched seven locations, including the headquarters of Mori Building Co., Sanwa Tajima Corp. and its parent company, Sanwa Shutter Corp., for evidence of professional negligence resulting in death. The manufacturer of the door is part of the Sanwa Shutter group.
The unusually prompt police action follows growing public concerns about the widely used automatic doors.
Roppongi Hills, which opened last April 25, is a popular business, shopping and entertainment complex that has seen more than 40 million visitors since its opening, many from outside Tokyo.
Tuesday’s searches, just four days after the death of Ryo Mizokawa, were apparently intended to collect evidence quickly in the wake of conflicting statements made by Mori Building and the door vendor and manufacturer, police sources said.
The use of automatic revolving doors has increased in recent years at large shopping complexes and other facilities, mainly because they help to keep the interior environment of a building steady. But there were no safety regulations for the doors and no previous reports of fatal accidents.
Speaking in a news conference after a regular Cabinet meeting, Land, Infrastructure and Transport Minister Nobuteru Ishihara indicated there should be government regulations to ensure the doors are safe.
Ishihara said he has also urged Mori Building to improve its safety measures until his ministry and the Ministry of Economy, Trade and Industry compile Japan’s first safety guidelines on automatic revolving doors. They are due by July.
The revolving doors at Roppongi Hills have injured 32 people since the complex opened, but none were reported to police. They only became known after the boy was killed.
An investigation determined that Mizokawa died after getting his head stuck between the door and the jamb as he rushed ahead of his mother at the second-floor front entrance of the Mori Tower building. The accident took place around 11:30 a.m. Friday.
The pair were visiting Tokyo from Suita, Osaka Prefecture, where they live.
The original setting for a safety sensor in the ceiling above the door to detect people or objects standing 80 cm or taller had been changed to 135 cm or taller to prevent the door from stopping unnecessarily following consultations with the building’s operator.
Sanwa Tajima said the change was made after the system kept responding to a 90-cm-tall safety barrier that had been erected in front of the door following an accident Dec. 7 when a 6-year-old girl was injured.
A second sensor in the door picks up objects up to 15 cm from the ground, but apparently did not detect Mizokawa as he is thought to have entered the door head first while the entrance narrowed. Mizokawa, who was 117 cm tall, got his head stuck at about 1 meter off the ground.
The door also does not halt immediately when motion is detected but continues to move for about 25 cm before stopping.
There are more than 300 domestically made revolving automatic doors installed in Japan, according to Ishihara.
Mitsubishi Estate Co. said Tuesday it will remove all revolving doors installed in the buildings it owns, in response to a fatal accident last week involving a 6-year-old boy at the Roppongi Hills complex in Tokyo.
The developer has shut down 19 revolving doors installed at major shopping-office complexes nationwide, including seven at the Marunouchi Building outside JR Tokyo Station and six at the Landmark Tower in Yokohama.
Mitsubishi officials said the doors will be replaced with less dangerous alternatives. The firm will not use revolving doors in future buildings, they said.
They said during a news conference that 12 accidents have occurred at their facilities, including two that required an ambulance.
In March 2003, three or four children rushed into a revolving door at Landmark Tower. One of the children slipped on a wet floor and got his right leg stuck between the bottom of the door and the floor, breaking his leg.
In 1993, a 6-year-old boy got stuck inside a different revolving door of the same type at the mall, they said.