1.   An unprecedented emergency halt to air traffic crippled overnight shipping and stranded traveling executives.

2.   What warrants an emergency halt?

3.   Bush had asked for an emergency halt to the recounting on constitutional grounds, arguing that it treats voters differently based on where they live.

4.   Bush had asked for an emergency halt to the recounting pending his constitutional challenge to recounts requested by his Democratic opponent, Al Gore.

5.   Bush had asked the federal court for an emergency halt to the manual recounting.

6.   Then on Wednesday a reactor at a nuclear power station in southern Ukraine came to an emergency halt because of what the authorities said were personnel errors.

7.   The driver of the train brought it to an emergency halt and went to help the injured, the SNCF railway company said.