From CNN 10.

Today, A special 12 minute episode of CNN10: We’ll take a look back at Hurricane Katrina– as the nation marks 20 years since the deadly storm made landfall on the Gulf Coast. We’ll break down what made the storm so devastating, and hear from Dr. Sanjay Gupta about his experience reporting from New Orleans’ biggest hospital. Plus, CNN Meteorologist Allison Chinchar will help us understand the science behind the catastrophic storm.