It is impossible to predict how a collision with a semi truck will turn out for those involved. All the usual factors that affect a wreck — the speed, the direction of the crash, the weather conditions and the relative safety features of the vehicle — are all involved, of course. So is the incredible size and mass of the tractor-trailer itself. One would think that the sheer size of the vehicle would make any outcome obvious, but two stories from the last few days show just how unpredictable such an accident can be.

The first story ends happily enough, thankfully. In Yuma, Arizona, a semi truck driver was attempting to turn at an intersection. The driver apparently miscalculated how much space the turn would require, and ended up driving over the front of a car stopped at the intersection, crushing part of the vehicle. Fortunately however, the five teens inside the car were unharmed, though perhaps understandably shaken by the experience.

The second story is less heartening, reminding us that for all the miracles, there are still disasters. The Ohio State Highway Patrol reported a collision between a PT Cruiser and a tractor-trailer on Ohio’s I-76. The crash happened when the driver of the Cruiser changed lanes and the semi truck rear-ended his vehicle when the driver failed to slow down. Both vehicles veered to the right and came to a stop off the road, and the driver of the smaller car was pronounced dead at the scene of the accident.

Notably, alcohol was not reported as contributing to either of these cases. The investigations are still ongoing into the matters. Did the teens stop too far forward at the intersection? Did the driver of the cruiser look before moving into the lane? Or was the contributing factor the sleep deprivation that all too often affects drivers of semi trucks under pressure to meet their deadline? Whatever the answers, the point remains that drivers must always understand that driving near a semi truck is not an experience that can be taken lightly.