Authorities say the Cadillac collided with the big rig near Lancaster, in the area of 90th Street West and Avenue A, at about 5:20 p.m. Officers believe the Cadillac driver ran a stop sign and was broadsided by the big rig tanker.
All four people in the car were declared dead at the scene. The driver of the big rig was not injured, but he was visibly shaken.