In the background, a picture of a grey spherical asteroid covered in craters suddenly appears on a computer screen. We really have no idea how many asteroids are out there. But there is a real possibility that, one day, we will find an asteroid that is on a collision course with the Earth. That depends on the size of the asteroid. A small one might destroy a small town, a really big one could destroy continents and trigger worldwide climate change.
Flames lick around the side as it enters the atmosphere.
In the distance, a dam. Distant roaring sound, they look up. Wall of water starts to rush down the valley. Shots of family in cab of the truck, racing down a bumpy road, with wall of water following them close behind. Car swerves behind a hill, water shoots past behind them.