Impressions in the ditch are the only signs remaining where a school bus rolled over south of Sweaburg in Oxford on Tuesday morning, March 5, 2024. Yet there was also a long length of tire marks preceding the rollover and these provided some clues as to the actions of the school bus driver before the rollover.

A full-size International school bus rolled over into a ditch of Dodge Line just south of its intersection with Cuthbert Road in Oxford County Ontario on the morning of Tuesday, March 5, 2024. The usual tight-lipped approach was applied by investigating police but eventually some seeming contradictions spilled out. Initial reports came out that a child became trapped underneath the school bus and that the child was air-lifted to hospital. One of the news agencies reported that Orgne Air initially reported that the child had critical injuries. These facts would normally indicate a dire outcome. However police then confirmed that “all the students were OK”. Even the child that was airlifted was done so as a precaution because of a concern of possible internal injuries. But questions remain.

If the child was trapped under the bus then the child must have been ejected from the interior of the bus. But that was never clarified. Modern school buses have been designed with “compartmentalization” that is supposed to replace the need for seat-belts. This long word “compartmentalization” could only have been coined by someone who did not care if the average person could pronounce it, let alone understand what it meant. But simply, the word means that an attempt is made to keep children in individual compartments, like eggs in an egg carton. Rather than being thrown around the interior of the bus higher seats are designed to keep children within the area in which they are seated. Protective padding is also within the seats to minimize the forces (“loads”) exerted on the children’s bodies. Windows are also designed to minimize the chance of ejection. Opinions have been raised that compartmentalization does not work, or works poorly, and that seat-belts should be installed and used. This discussion has been around for many years now.

A new call for seat-belts has been ignited over the result from this present school bus rollover, even though there is little information about what happened to the child that was trapped under the bus. Police were the only ones with access to both the school bus and the collision site when the evidence was fresh yet they have said nothing that would help to understand what happened.

The next group of persons with some information are the news reporters who attended the site. Although they take various photos and videos they often do not understand the meaning of the evidence they document and so important evidence is often not illuminated or is left sitting in some reporter’s digital storage.

Yet a single photo of the right side of the bus was taken and shown in an article by reporter Jacquelyn LeBel, of Global News, which caught our attention. Unfortunately we cannot show this photo because it is copyright and the reporter herself did, or could not, reveal the important evidence that the photo showed. The photo was taken of the school bus after it had been righted and was on the hook of a tow truck. There was earth and debris still clinging along the side of the bus. The photo showed that four rectangular windows had been broken out. And then, importantly, a fifth window was not only broken but the actual frame of the window was pulled out and upward. This fifth window was the front emergency exit window. There are two emergency exit windows on the right side of such buses and the rear one was intact. The important question is: why was this emergency window pulled out in the manner that it was? Yes, it is possible that it became that way during the towing procedures while lifting the bus from its side. But why was this single window pulled out and not any other? Coincidence? Well, possibly. But it could also explain how a child might have exited the bus and become trapped underneath it. Although a small child’s body might still exit through any of the other four broken windows the probability is less because there is a metal frame running forward-back across the windows which makes the possibility of ejection less likely. Many years ago agencies such as Transport Canada were aware of the possibility of ejection through side windows and so designs were changed so ejection was less likely. So, although ejection through these windows cannot be totally ruled out, in my view, it is not likely.

Upon seeing the concerning evidence of the deformed and protruding emergency window I decided to attend the collision site to gather further information. This site examination was begun at my arrival at approximately 1445 hours, or some seven hours after the time of the collision. Police had already left the site and the bus had already been towed away. What was remaining were a couple of SUVs from CTV News and an unmarked SUV belonging to an unknown reporter. Since I parked by vehicle near the CTV News vehicles I happened to engage in a conversation with one reporter while I was still several hundred metres from the collision evidence. I mentioned the issue of the damaged emergency window and lamented that I could not examine the bus to explore the issue further. The reporter said he had taken some close-up video of the window and he showed that to me. In the video I could see an important point: The damaged emergency window contained a release latch at the bottom of the window frame. This was an important clue to what might have happened. I explained that older International school buses were equipped with release latches at the bottom of the emergency windows. Newer buses had latches that were on the side of the frame roughly up the middle of the window. An example of the older style release latch is shown in the photo below.

And the newer style of release latch is shown in the photo below.

To understand the important of this point, one needs to consider how the older style latch could become opened during or prior to a collision.

First point to be made is that, if a release latch is even slightly ajar an alarm will sound like a high-pitched squeal. It is very distinctive and a bus driver would immediately recognize that one of the emergency exits, including the rear door, was not closed properly. So it is unlikely that the older style latch was ajar prior to the collision events. But how could it become released during the collision events? One needs to look at the collision site to obtain some clues.

The photo shown below was taken by Gorski Consulting during our site examination. It is a view looking north from approximately 150 metres south of where the bus came to rest. A 50-metre, metal measurement tape was placed along the roadside commencing at the point of the first visible collision evidence. This first evidence was in the form a tire mark from the right side tires of the bus as it exited from the pavement and onto the very narrow shoulder.

Unfortunately, someone’s vehicle had already ridden over top of the beginning of the tire mark and so we can only estimate that the original commencement of the tire mark was likely an additional 5 or so metres behind the camera.

The next view, below, is showing the site in the opposite (southward) view. The right side tire marks from the bus should be clearly visible here as the bus came to the edge of a steep drop-off of the shoulder then it veered back onto the pavement. The point where it crossed back onto the pavement was about 85 metres north of where the bus initially exited the pavement.

Turning around again to face north the three photos below show the tire marks of the school bus as it returns onto the pavement, crosses over the roadway centre-line, and then arcs back around to the right ditch where it rolls over.

As a point of clarification, there was another set of curving tire marks that were visible just behind the reporter’s white SUV as shown in the northward view below. In my opinion these marks were likely not collision related. Certainly they were not caused by the bus. As they terminated at the edge of the shoulder it is my speculation that they could have been caused by the dual wheels of an ambulance or perhaps a tow truck. But further information could clarify their origin.

To complete this process the photo below shows a general view of the markings at the final rest position of the bus.

So, to summarize, we have the bus initially travelling onto the right shoulder and it almost fell over its the steep edge. But it returned onto the opposite site of the road and then returned to rollover in the right ditch. This occurred over a distance of about 150 metres. While 150 metres is not a short distance it is also not excessive. Several sites that I have examined, particularly on high-speed expressways have shown loss-of-control tire marks over distances of as much as 400 metres.

But let us put some broad numbers together to estimate speed. The “fish-tailing” tiremarks that persons are used to describing are technically called “yaw” marks. Yaw is the motion whereby a vehicle rotates about its vertical centre-of-gravity. In almost all instances of vehicle rollover there are indications of yaw preceding the rollover. The deceleration during yawing can be various depending on the extent of rotation and whether any braking was actually involved. Since this is not a matter being presented at a trial we can simply use an overall deceleration value of 0.3g over that 150 metre distance. This would result in a speed of about 107 km/h for the bus at the beginning of the visible tire-marks. One should not read more into this than is reasonable. This speed estimate is based on a very broad and general deceleration. The actual speed could be considerably less depending on what further details are uncovered. It has been presented to suggest that there is no basis, given the present facts, to conclude that the bus was travelling at an excessively high speed.

Given that the bus was likely travelling at a typical, highway speed we can also examine the severity of the rollover. It can be noted that the bus remained on its wheels up to the time that it reached the steep drop-off at the right edge of the shoulder. From that point the bus came to rest a short distance on its right side. This suggests that the rollover occurred when the bus was travelling at relatively slow speed, possibly in the range of 10 to 20 km/h. This suggestion is supported by what was visible at the point where the bus came to a stop.

When glass shatters when a vehicle is travelling relatively quickly the individual shards of glass can be strewn for a long distance. At low speed such glass can be deposited in a way that one can recognize the contours of the glass frame from which the shards came from. The latter is what was visible at the bus rest position.

For example the photo below shows a concentration of broken glass where the contours of the window from which it came are clearly defined. It is clear that this glass came from one of the four rectangular windows that were fractured.

And this finding is repeated in another area of fractured glass shown below. The rectangular contours of the window from which the glass originated are clearly defined.

So the window fractures occurred when the bus was travelling very slowly and they did not occur until the bus fell onto its right side essentially when the bus was stopped.

There was an area of glass which was less defined which we suspect came from the front emergency exit window. This area of glass is shown below. The fact that the contours of the glass are not as defined indicates that the emergency window had come to be open when the bus fell onto its right side.

So, to summarize, it is believed that the bus was travelling at a typical, highway speed when the first tire marks became visible. We also conclude that the bus was travelling very slowly when it eventually rolled over. But how could a child become ejected in this scenario? This becomes difficult to explain given that we have not had a chance to examine the bus and so many other sources of evidence are not available to us. So the following comments have to be treated with caution.

For the present time we assume that the reports that the child became ejected are correct. The reports that the child became trapped under the bus are of concern as to their reliability since, being ejected and trapped under a full-size bus should not result in minor injuries.

One has to examine what might happen to children who are unrestrained while the bus is going through its pre-rollover motions. Firstly the bus travels onto the right shoulder to the point that it almost rolls over because it is at the extreme edge of the drop-off. Being at this edge would cause the bus to tilt to its right side while it is being steered back onto the pavement. In this scenario the children seated at the right side seats of the bus would be expected to be pushed toward the right interior wall of the bus. A child seated at the front emergency window would also be expected to be pushed against the bottom latch. And since the bus would be at a substantial angle, with its right side down, it could be easily understood how a child’s body might move upward while pressed against the latch, thus rotating the latch to an open position. But that is not the only time when which situation could occur. The situation could also occur at the point when the bus is rolling over the steep drop-off near its final rest position. In fact, near the final rest position the bus would be at a very steep angle with its right side very low and the child’s body could be moving upwards in relation to the latch. So the opening of the emergency window could also have occurred very close to when the bus was rolling over. These comments are very broad and a proper reconstruction would need access to the bus which is not available.

The concern that children could be ejected from a full-size bus on regular basis is somewhat unfounded. Newer buses no longer have the latch at the bottom of the emergency exit window. In a brief survey of school buses in the London area we could not locate another, old style, International bus with such bottom latches. So this scenario is rare and likely to be rarer as older buses are replaced with new ones.

The history of my opinions of seat-belts on school buses remains that I have warned against such installations. Primarily because I know of the dangers that exist when children do not wear seat-belts properly. And unless supervised on a constant basis children, invariably, will not wear seat-belts properly. What most persons do not understand is that the lap portion of a seat-belt is difficult to keep below the iliac crests of the pelvis. In other words the lap belt will sit to high across the child’s abdomen and this is very dangerous. I have said many times that, in a major collision, with a relatively high change-in-velocity, a child will sustain major abdominal injuries and will require immediate delivery to a hospital operating room. If several children sustain such injuries and if the collision is in a rural area the changes of survival would be dim.

However, while I do not recommend seat-belts, I do recommend restraints. In other words some form of restraints are needed that are similar to child seats and or booster cushions for older children. This is not an easy process because of the varying sizes of children and getting them into the proper type of restraint. And the costs become prohibitive.

But I also do not believe that compartmentalization is a satisfactory solution. Due to the large mass of a school bus the argument is correct that most impacts will not result in a large change-in-velocity of the bus. But in rural settings at highway speed loss-of-directional-control of a school bus is not a rarity. As shown in the present collision it is common. In such instances lateral forces are generated and children become thrown against the sides or roof of the bus. In a majority of instances injuries caused during these motions are not life-threatening. But incapacitating injuries, including spinal cord injuries are not as rare. An unrestrained child striking its head against a hard surface can cause the dislocation of the head that could produce cervical spine injury. Not something to be taken lightly. So, as difficult as it may be, transportation safety agencies must come to develop a proper restraining system for children on school buses. But not your typical seat-belts.