This is a case of driver negligence and stupidity, not an unsafe vehicle. No, that vehicle is just unsafe. At 40mph into a barrier those in the front sustain serious, possibly critical, injury, where in safer cars there would be little or no injury. The problem is that the cabin collapses onto the occupants, and depending on the year of the car, the door pops open to let the occupant's head through.
We are all aware that the Ford Explorer has its design problems, and safety problems. The point is, ANY vehicle that is out of control at over 90 MPH is unsafe! These people would likely have died if the driver were driving anything short of a Bradley Tank.