Investigators search for answers after South Korea plane crash

Crews continue sifting through debris after a plane crash-landed and burst into flames in South Korea on Sunday. It's not clear what caused the disaster, which left 179 people dead and only two survivors. The Boeing 737-800 was flown by an experienced pilot with more than 6,000 flight hours under his belt. Authorities say the jet received a bird strike warning just before the crash.