11.   Schools also closed early yesterday in South Dakota, where vehicles slid on ice-covered roadways and even truckers pulled over to wait for conditions to improve.

12.   Schools also closed early yesterday in South Dakota, where vehicles slid on ice-covered roadways and even seasoned truckers pulled over to wait for conditions to improve.

13.   The two vehicles slid into a ravine, and the truck driver was killed, said U.N. officials.

14.   Three relief workers and their Albanian driver died earlier this month when their vehicle slid into a ravine.

15.   Tractor-trailers jackknifed and vehicles slid off frozen highways.

16.   In France, the driver of a road-salting vehicle was killed when the vehicle slid on black ice.