Black Americans are nearly twice as likely to have high blood pressure, diabetes, and heart disease than White Americans, and their life expectancy is about five years shorter. Why? In this special feature-length documentary, Oscar-nominated filmmaker Stanley Nelson investigates the dramatic health disparities in the U.S., even as scientists confirm that there are no meaningful genetic differences between races. From the deep history of pseudoscientific beliefs about race that still permeate modern medicine, to the latest research on how experiencing discrimination can directly damage the body's DNA and biology, "Critical Condition" reveals the factors behind the health crisis facing Black Americans.

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 first episode of this two-part special, go behind the scenes as scientists make a series of high-stakes decisions to ensure the ambitious experiment goes off without a hitch. They only have one shot. The plan is for 8 drivers to drive 8 different cars by remote control at 70 mph down a hazardous straightaway. But how can they best represent real-world conditions to create a crash, especially when the drivers have no idea what's about to happen? How do they ensure that the remote drivers feel natural behind the wheel? And what is needed to fully capture every data-point possible? The intense preparation for the most ambitious crash test ever conducted culminates in the moment of truth as the cars barrel down an airport tarmac and collide in a massive, multi-vehicle pile-up.