Surprisingly little is known about the behavior of cars and drivers in uncontrolled, real-world accidents, despite rigorous testing in laboratory-controlled crashes. Now, a first-of-its-kind experiment aims to discover what really happens in a multi-vehicle pileup and how cars and driving could be made safer.

In the second episode of this two-part special, forensic analysis is put to the test. Real-life crash scene investigations have very little data to work with, so are they accurate? And what can we learn about car safety when there is actual data to show exactly what happened? Follow scientists, engineers, and accident investigators as they analyze a treasure trove of data – more than they've ever been able to work with before. Interviews with drivers offer valuable clues into what they saw and how they reacted, and a LIDAR scan of the scene is stitched together into a digital version of the entire event that can be analyzed millisecond by millisecond. In this unprecedented look at a major multi-vehicle accident, discover insights about driver behavior and vehicle design that could save lives.