The Rock County sheriff's office is investigating a three-vehicle pile up on Highway 59, between East Vincent road and County "N". Deputies say it appears to have started after an 11-year-old boy pointed a toy gun outside a car window a little after 5:30 Tuesday night. Two drivers told authorities they thought the gun was real and slammed on their brakes. One vehicle swerved into an oncoming lane and hit a third, causing it to roll-over. Occupants of all three vehicles ended up in the hospital with non-life threatening injuries. No citations were issued, but the boy has been referred to juvenile authorities for disorderly conduct.