Computers are increasingly causing problems on Wall Street. We'll find out why investors are getting spooked. Then, sticking with scary, infectious disease experts are monitoring the Olympics for outbreaks, as millions of people descend on London for the Olympics. An interview with homegrown Olympics swimmer Jason Lezak. And, why is craigslist shutting down app developers who want to make the site easier to use? Plus, other news in technology with John Moe. And David Kipen is here to tell us how Southern California invented Mars.