The union authorized a strike to begin on January 1, 1952.

The city's teachers last authorized a strike in June 1993, after going 21 months without a new contract.

In May, 1970, the teachers again authorized a strike over salary.

The union contends that 93 percent of all the players have authorized a strike.

The teachers have asked their union to authorize a strike if safety does not improve.

Teachers again authorized a strike in May, 1967 over salary demands.

The order did not authorize offensive strikes in any specific countries.

Even if the pilots authorize a strike, it is not clear whether they can actually walk off the job.

So far, 11 of the 22 teams have voted to authorize a strike.

Now a simple majority will be sufficient to turn down a contract and authorize a strike.