 NTSB Chair Jennifer Homendy is urging parents to warn their teenagers about the dangers of driving after using marijuana. She cites a crash in Tishomingo, Oklahoma that killed six high school girls two years ago. The teens were riding in a tiny Chevy Spark hatchback, which collided with a gravel-hauling semi-truck. Toxicology reports found marijuana in the 16-year-old driver's blood. The other five were also positive. The agency recently released the final report on the March 2022 collision.