The October 2, 2013 church bus accident on Interstate 40 near Dandridge, Jefferson County, Tennessee that left eight dead and fourteen people injured will result in lots of people on the ground investigating what happened. The Tennessee Highway Patrol will be present, as well representatives of the liability insurance companies for the church bus and the tractor-trailer company. Representatives of the National Traffic Safety Board (NTSB) will not be present because of the government shutdown.
What data are the professional investigators looking for and what do they hope to accomplish by their efforts? First, they want to document the precise location of all physical evidence – the vehicles, tire marks, gouge marks, damage to medians and wire median barrier, protective devices, etc. All of this data will assist experts in determining the events leading to the crash and fire, and provide information about speed of the vehicles involved.
The investigators will attempt to download the "black box" information for each vehicle. Most vehicles these days have "electronic control modules" that capture certain data for a number of seconds before an event (and other data as well). Some older vehicles do not have ECMs, and some fail to work as contemplated, but an effort will be made to get the data if an ECM is available.