Officials are urging people to be cautious around ice-covered Midwestern lakes as temperatures rise this week.
The U.S. Army Corps of Engineers said in a news release Thursday that there is no such thing as 100 percent safe ice. The corps' Kansas City district urged people to watch for deteriorating conditions at its 18 lakes throughout Missouri, Kansas, Iowa and Nebraska.
The corps says it's impossible to judge the strength of ice by its appearance, thickness or temperature. Strength also is based on the depth of water under the ice, size of the water body, water chemistry and currents.
The corps also noted that ice seldom freezes uniformly. That means it may be a foot thick in one location but only an inch or two thick just a few feet away.