Police are investigating a powdery substance that was thrown onto an IPS bus Monday afternoon.
The bus driver told school officials a balloon filled with an unknown white, powdery substance was thrown through an open window and burst. The white powder spread on the interior of the bus.
Fifty students aboard the bus were transferred to a replacement near W. 34th Street and Lafayette Road. No students were injured.
The bus driver drove the bus to IFD Station 30 and asked for an investigation.
Initial tests of the substance by Hazmat crews showed it was 93 percent not positive for hazardous materials. Investigators sent the substance out for additional testing to be 100 percent sure. Results of those tests should be available by Wednesday.
Concerned parents of students on the bus should call the school in the morning.
Metro police detectives are investigating who was responsible for throwing the balloon onto the bus. Anyone with information is asked to call Crime Stoppers at 262-TIPS.