From oil slicks to pings from dying black boxes, each new lead provided a salacious morsel that drove viewers to wonder: An unmanned underwater submarine is now using sonar to comb the ocean floor at a depth exceeding 4 1/2 kilometers (2.8 miles) off the west coast of Australia. According to the latest survey by the Pew Research Center conducted April 3-6, the missing plane remained the top news story in the U.S., with 33 percent of people saying they followed it over a deadly shooting at Fort Hood Army base, developments related to Ukraine and President Obama's health care overhaul. A month and a half into the massive search that has involved scores of countries scouring thousands upon thousands of ocean miles, the plane was still among the top three stories Sunday on Google news. Part of the obsession may also revolve around the country's gotta-know-now mentality and its social media addiction that gets fed 24/7 by the latest breaking news, raw footage or photos going viral on Twitter, Facebook and YouTube. Since the plane disappeared, it has consistently been one of the top five most-read stories on The Associated Press' mobile app. A combination of popular TV shows and a history peppered with real-life detective dramas, from who shot President John F.