Matsuzawa, the arsonist.The cause of the fire was arson. The fire was set by Tatsuya Matsuzawa, 32, a part-time employee of the restaurant. On the day of the incident, he was working at the store until 5 p.m., just before the fire broke out. “The suspect Matsuzawa started working at the building materials store about a year ago. He had a quiet personality and was not the type to make much of an impression. On the day of the incident, he was working from noon, taking out products and making rounds. He was very familiar with the store and had probably planned in advance where he would set the fire. He told the police that he started the fire in the work shoes section, which was not captured by the security camera.” Based on the testimonies of employees and customers, the suspect Matsuzawa, who left the store in an unusual manner, emerged in the line of investigation. The motive for the crime was appalling. He told the police that he did it because he was stressed at work.   On the day of the incident, the wind was blowing at a maximum speed of 8.9 meters per second. One wrong move could have resulted in a catastrophe involving the surrounding residential area. Takao Sakaguchi, executive director of the Citizen’s Disaster Prevention Research Institute, points out the dangers and precautions to be taken in the event of a fire in a large store. “Stores such as home centers are large and contain many flammable items such as plastic products and wood. Large quantities of paint, thinner, and other items classified as hazardous under the Fire Service Law are also placed there. Once a fire starts, there is a danger of the fire spreading explosively. It is a similar situation to gasoline burning.” “Upon entering the restaurant, you should check the location of emergency exits and make sure you know the evacuation route. Smoke contains toxic gasses. If a fire breaks out, you should evacuate by covering your mouth with a handkerchief to prevent smoke inhalation.” The police are working with the fire department to investigate the scene with a view to possible trouble between employees.