Tracing its origins to the Air Commerce Act of 1926, the National Transportation Safety Board (NTSB) was established in 1967 as an independent agency inside the U.S. DOT charged with investigating why transportation accidents happen. In 1974, it became an independent federal agency separate from the DOT. Although largely focused on aviation, the agency also investigates roadway, marine, pipeline, and railroad accidents, as well as those involving commercial space. Today, we talk with Robert L. Sumwalt—currently executive director of the Boeing Center for Aviation and Aerospace Safety at Embry-Riddle Aeronautical University and former chair of the NTSB—about that agency’s ongoing mission to investigate accidents and recommend improvements that make travel safer for everyone who uses our transportation network.