(Union Co., IL)  —  An investigation is underway following a single-vehicle crash in Union County that killed three people including an 18-month-old girl.  Police say a car was traveling on Shiloh Road on Wednesday when it veered off and hit a pole and a tree near Makanda.  Officials say they are 28-year-old Cassandra Payne of Herrin and 28-year-old Derrell Smith of Belleville. A one-and-a-half year old girl also died in the crash. Her name was not released. A fourth passenger was hospitalized. They were all wearing seat belts.