Dark Tower- I assume you mean an asteroid hitting Earth in 2014. An Earth killing asteroid WILL hit Earth eventually, and most likely very soon, although the odds of it happening in 2014 specifically is very small. The last major collision was 65 million years ago, and that caused the extinction of nearly all animal species on Earth. A smaller, yet still significant, impact happened about 17,000 years ago, which is believe to have quickly ended the ice age and caused the extinction of many ice age animals (like the mammoth, saber toothed tiger, etc). We're due for a large collision soon in geological terms, although I severely doubt it will happen in our life time.
And if you all want examples of what asteroids can do, look at Mars. Mars used to be a lush planet with running water and an oxygen rich atmosphere, much like Earth. It's now believed that 3 imcomprobably big asteroids, measuring, I believe, 10, 20 and 40 or so kilometeres across, crashed into the southern hemisphere of the planet. It destroyed Mars's atmosphere, evaporated it's water, created Olympus Mons (the solar system's largest volcano) through volcanic activity, created the gigantic canyon (again, the largest in the solar system) through intense stress and created 3 huge bulges on the opposite side of the planet. THAT'S what could happen to Earth.