RedactedNarrative: On 07/09/16, at approximately 7:28PM a 911 call was made for a jet ski accident on the Kankakee River near the Des Plaines Conservation Area boat launch.  Subject1 was operating a Yamaha jet ski (exact vessel is unclear at this time) with her daughter, Subject2, riding on the seat behind her.  Subject3 was operating the other Yamaha jet ski (exact vessel is unclear at this time as the pairs were switching jet skis all afternoon) with her daughter, Subject4, sitting on the seat behind her.  The exact details are still unclear, but the two jet skis were riding almost parallel heading eastbound (upriver) and turned colliding with each other.  Both Subject2 and Subject4 were thrown off the back uninjured, while somehow Subject1 and Subject3 were impacted in their lower backs and pelvis.  Subject3 and Subject4 remained in the water with bystanders while a boat towed Subject1 and Subject2 to near shore.  Wilmington and Troy EMS arrived and removed Subject1 and Subject3 from the water and transported them to St. Joseph's Medical Center in Joliet.  Subject3 was x-rayed and then transported to Loyola Medical Center in Maywood for a bleeding fracture in her pelvis and broken sacrum. She underwent surgery on 07/11/12.  Subject1 suffered a fractured pelvis and broken sacrum, but was expected to heal and was released on 07/12/16.
  
  On 07/16/16, while conducting a follow-up interview with Subject1 she admitted they had been lying about the accident to protect their daughters.  I re-interviewed all the people involved and their stories all matched.  Subject1 was the operator of vessel 1 with Subject3 riding behind her as her passenger.  They were sitting near the middle of the river parallel to the launch waiting for an open spot at the dock.  They began to move forward and turn towards the dock at a slow rate of speed.  Subject4 was operating vessel 2 with Subject2 behind her as her passenger.  Vessel 2 was driving full throttle towards and to the left of vessel 1.  When vessel 1 began to make the turn Subject4 on vessel 2 let off the throttle and tried to turn away.  Subject2 hit the engine cut off button in an attempt to stop.  Vessel 2 hit the occupants of vessel 1 at almost full speed.  The bow of vessel 2 ran over the backs of Subject3 and Subject1 knocking them into the water.  Subject2 hit her right side of her forehead off of the back Subject4's head when the impact occurred before they were both thrown into the water.  The hull of vessel 2 glided over Subject3 back again while she was in the water.  Subject2 and Subject4 insist the throttle had stuck open on vessel 2 when Subject4 released it, but they were unable to steer. Subject2 said she had to pry it out with her fingers. The only damage to either vessel was minor cracked fiberglass and paint on the underside bow rub rail of vessel 2.  Subject4 was not allowed by anyone else to operate.  Subject2 was supposed to operate with Subject4 on back, but they switched when the parents were out of site.
  
  I later inspected vessel 2's throttle and found that it was not sticking or hindered in any way.  Subject1 said that they had been unaware of how to work the choke and that Subject2 had pulled it out earlier when they started the jet skis and she may have been confusing that with the throttle. I did find the choke on vessel 2 was pulled out, opening it up all the way.  I was unable to find any mechanical failures on either of the jet skis.
  