I have been very critical about the claim of altitude sickness being the cause of the crash that killed two Japanese civilians by a U.S. naval officer. After reading this really good article from Military.com about the accident, I am more convinced then ever he just simply fell asleep at wheel:
Navy Lt. Ridge Alkonis was driving his car, filled with his wife and their three children, down from the heights of Mount Fuji on May 29, 2021. It’s an iconic destination for both Japanese and foreign tourists alike, a peak that serves as a sentry over much of central Japan.
Alkonis and his family had taken the trip at the request of his second daughter, spending an hour near the summit before planning to go to a dairy farm in the foothills that sells pizza and ice cream.
As they descended the mountain, Alkonis felt something was wrong but chose to keep going because they were very close to the next town, he would later testify at his trial.
He lost consciousness right as the vehicle approached a roadside noodle restaurant, swerving into the parking lot and hitting three parked cars, pushing one into a fourth vehicle, before crashing into a fifth and final car. Between the layers of metal, two Japanese nationals, an 85-year-old woman and her 54-year-old son-in-law, were crushed. They both died.
Two members of the Alkonis family were taken to a local hospital, but the sailor himself did not receive medical attention. All have made a full recovery. Today, Alkonis sits in a Japanese prison, serving a three-year sentence after being convicted of negligent driving.
That’s the part of the story that no one disputes. It’s the other parts — why Alkonis lost consciousness, how he’s been treated in Japanese custody — that have drawn in lawmakers, led to accusations of a “false” conviction, and even put pressure on the legal agreement that governs U.S. service members’ presence in Japan.
Military.com
The big thing to take from this passage is that he did not even go to the summit of Mt. Fuji which has an altitude of over 12,600 feet. Instead he just drove to one of the stations where hikes begin at about 7,000 feet. People travel to cities like Colorado Springs in the U.S. that is near 7,000 feet every day and you don’t see them crashing vehicles due to altitude sickness.
Additionally the accident happened in Fujinomiya which is almost near sea level. Altitude sickness gets better when losing altitude not worse. I think he got up early to drive to Mt. Fuji from his home in Yokosuka and simply feel asleep at the wheel after a long day of driving.
I highly recommend reading the rest of the article because the claims made by his wife and her Congressional supporters conflict with the facts of the case. The Japanese put a big emphasis on self responsibility and all the excuses is probably why he will not be released early.