There were 2 separate accidents Friday late afternoon at Interstate 64 and Highway 51, one leading to the other.  According to Illinois State Police Trooper Joey Watson out of District 13, there was a 2 car accident with no injuries that had vehicles stopped and slowed in the area.  A car driven by a 22-year old male from Pana was stopped and there was a car behind him driven by a 20year old female from Centralia, while a pickup truck driven by a 39-year old Ashley man was behind her.  A 4^th vehicle, a car driven by 24-year old Casey Pingsterhaus of Richview did not stop or slow down and struck the pickup from behind.  This caused a chain reaction of the 4 vehicles.  Pingsterhaus received serious incapacitating injuries, as did a male youth in the car.  Both were taken to a local hospital.  The man from Ashley in the truck also suffered incapacitating injuries and was taken to a local hospital, but his passenger was not injured.  The male from Pana was not injured and the female from Centralia in the car behind him was not injured, but a female youth in that car was injured and taken to a local hospital.  Pingsterhaus was cited for Failure to Reduce Speed to Avoid an Accident.  Trooper Watson says Pingsterhaus may have had a medical issue that may have led to the crash.  She also had a service dog that fled the scene.