Tornado Alley Twister

S1, E2: WWhat happens when the most intense tornado ever measured strikes Dallas, Texas? With winds clocked at 318 miles per hour, the monster twister carves a path through the city up to a mile wide. It happened once before, just two hundred miles to the north in Oklahoma City. There in May 1999 a "Megatornado" scoured the earth for 85 minutes along a 38-mile path. 43 people died and property damage was enormous. It became history's first billion-dollar tornado. But in more-densely developed Dallas, the scenario is worse: as many as a thousand dead... and FIVE billion dollars in damage.