In the first surveillance video, a family can be seen walking on the road, not the sidewalk. It seems to be at night. As they walk off screen, a truck suddenly comes smashing through some parked vehicles. Left behind the trucks trail are the crushed bodies of the family. The second video comes from a random person's phone at the site of the accident. You can see all the bits and pieces of the family's flesh scattered around the area, stuck under the other vehicles that also got destroyed by the truck.