1.   A walkout threatened to cost millions of dollars and strand passengers coast-to-coast at the start of a busy holiday weekend.

2.   A walkout threatens to cost millions of dollars and to strand passengers at the start of a busy holiday weekend.

3.   But with talks paralyzed in Canada, the walkout threatens to produce a massive wave of layoffs in the coming weeks.

4.   A walkout threatened to cost millions of dollars and strand passengers from one coast of the United States to the other at the start of a busy holiday weekend.

5.   The Belgian airline Sabena asked a court Friday to force striking pilots back to work, arguing their walkout threatened the future of the troubled carrier.