Another round of tornadoes tore through Oklahoma on Friday night. While all of those storm videos popping up on YouTube and television are incredible to watch, they're also obviously very dangerous to film. Thirteen people died in Friday's tornadoes, including veteran storm chaser Tim Samaras, his son Paul and their colleague Carl Young.
For years, Samaras has driven into the heart of tornadoes, equipment in hand, to learn more about them. Late last month, as tornado season was opening in Oklahoma, Samaras talked to National Geographic about what motivated him to engage in such dangerous work--starting with a boyhood viewing of "The Wizard of Oz." It was our last interview with him, and one of his final interviews before his untimely death.