Photos of the scene after the accident show the intensity of the fire and impact.
The large bus that caught fire was charred black, and the area where the driver was sitting was heavily caved in. The highway divider where the bus collided with the driver was severely damaged.
The accident occurred shortly after 10:00 a.m. on August 22. Near the Toyoyama-minami exit of the Nagoya Expressway in Kita-ku, Nagoya City, Aichi Prefecture, a bus crashed into the side of a roadway and plunged into the roadway divider, overturning and bursting into flames. A passenger car was also involved. The fire was extinguished in about an hour and a half, but two people were killed and seven others were injured.
“One of the two who died was the 55-year-old driver of the bus. He had been a driver for about four years. He was extremely serious about his work and was never late for work or absent without permission and he had no abnormalities when he was checked for alcohol before going to work.
The bus has a capacity of 61 passengers, but the number of passengers on board on the day of the accident is unknown. The bus was operated by Aoi Kotsu (Komaki City, Aichi Prefecture). The bus was on its way from Sakae, the center of Nagoya, to the prefectural Nagoya Airport,” said a reporter from the society section of a national newspaper.
Possibly falling asleep or unconscious
According to eyewitnesses and other witnesses, the bus was panning and burst into flames. About 10 passengers were sitting on the highway and were being treated by emergency personnel.
Some testimonies say that the bus was driving unsteadily before the accident. Although we cannot be certain, it is possible that he fell asleep at the wheel or lost consciousness for some other reason.
One possible cause is sleep apnea syndrome (SAS). In January 2015, 11 people were injured when a bus collided with a utility pole in Tokyo, and in November 2017, a bus ran into a pillar of an overpass in Kanagawa Prefecture, killing one person and seriously injuring six others. Both drivers were found to be suffering from SAS.
What are the symptoms of SAS, which is common among drivers? Takeshi Tanigawa, a public health specialist and senior professor at Juntendo University Graduate School, explains.
He says, “During sleep, breathing stops many times, and the quality of sleep declines. As a result, SAS causes intense sleepiness and fatigue during the day. SAS is classified into mild, moderate, and severe according to the number of times a person stops breathing: 5 to 20 times per hour of sleep when a person stops breathing for 10 seconds or more is mild, 20 to 40 times per hour is moderate, and 40 times or more is severe.
The number of patients with moderate or severe SAS in Japan is said to be as high as 3 or 4 million. Including patients with mild SAS who are not covered by insurance, it is estimated that 10% of the adult population, or about 10 million people, are affected. Drivers in particular need to be careful, as they can fall asleep at the wheel and cause serious accidents that can take lives. The problem is that most patients are unaware that they have SAS. According to a study in the United States, nearly 80% of people with SAS are unaware that they have it.
According to Tanigawa, there are four main factors that contribute to SAS.
“The first is a small jaw structure. The airway for breathing is narrow. Second is obesity. In my survey of about 5,300 truck drivers, those with a body mass index of 30 or higher were 4.4 times more likely to have SAS than those with a standard body mass index (18.5 to 24.9). This is because fat narrows the airways. The airways are widened by the surrounding muscles, which weaken with age.
The fourth is alcohol and tobacco. Alcohol relaxes the muscles, and smoking causes inflammation of the airways. A common symptom among SAS patients is snoring loudly. If a family member points out to you that you snore too loudly or that you don’t breathe when you sleep well, I recommend that you see a doctor.”
If you can think of anyone who has this problem, you need to be careful. According to Tanigawa, there are specialized devices to widen the airway and treat breathing problems during sleep. The symptoms should be corrected before a life-threatening accident occurs.
Photo by： Kenji Natsume