John Warner surveys the damage near a friend's mobile home in the Steelman Estates Mobile Home Park, destroyed in Sunday's tornado, near Shawnee, Okla., on Monday.
Tornado strength is currently measured on what is called the Enhanced Fujita Scale, which gives the tornado a rating from 0 to 5 based on estimated wind speeds and the severity of the damage.
May 16, 2013 A recently published study found slightly elevated amounts of inorganic arsenic in samples of chicken meat purchased at grocery stores. Arsenic-based drugs are no longer used in chickens — but they are still used in turkeys.
May 16, 2013 Scientists have discovered water that was sealed in Canadian bedrock for nearly half of Earth's history. It may contain the descendants of ancient microbes. The discovery could give scientists new insights into early life on Earth and inform the search for life on other planets.
May 15, 2013 Fish are moving away from the equator and toward the poles to maintain their preferred water temperature. That means, for example, that fishermen are seeing swordfish normally found in the Mediterranean swimming near Denmark. But in the tropics, there are no fish to replace the ones that are leaving.
May 15, 2013 Waste and recycling handlers in Portland, Ore., say they're seeing an unfortunate side effect of the city's reduction in garbage pickups: 120 pounds of dirty diapers a day, tucked into recycling bins.