Our hearts continue to go out to the survivors, families, friends and first responders who have been the victims of this terrible tragedy. It is our hope that answers will soon come to the many questions as to why it occurred, and lead us to take steps to mitigate its re-occurrence in the future.

Disclaimer:  I am by no means an accident re-creation expert, nor have any experience in accident evaluation, but the circumstances of the tragedy are intriguing, and thus I wanted to see what I could empirically construct from publicly available information, basic physics with assumptions, and some modeling and simulation.

PreCrashGeometry

The facts:

  • The semi was moving westward on Hwy 335
  • The bus was moving northward on Hwy 35
  • The approximate time of the incident occurred at 5pm Saskatchewan time
  • There is a stop sign on the Hwy 335/semi route

The assumptions:

  • The bus and semi had relatively the same mass
  • The bus and semi had relatively the same velocity at point of impact
  • From available imagery, the bus struck the semi’s middle

Formula_Direction

This simplified, assumptive result would seem to coincide with available photos of the area post-crash.

We might also surmise, had the semi stopped at the intersection, but was in the process of accelerating into it, its velocity (with large heavy load) would have been small, rendering the above equation to provide a result closer to 90 degrees (which again, the photos do not seem to support).

Was the Sun a factor?

We certainly can determine where the Sun might have been relative to the semi at approximately 5pm Saskatchewan time.

SemiSun

According to local reports, it is generally thought that the Sun was too high to be a factor, and the above graphic seems to support this. However, the Sun’s rays can reflect off of many things such as snow, water, windshields, mirrors, etc. So, we do not really know if some kind of indirect sun-ray may have affected the semi driver.

I have no doubt that there are many other facts and factors about this incident that will soon be revealed, and thus will shed enough light on the causes of this tragedy to provide closure for some, and lessons for others.

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