The gates of a school bus yard are locked after drivers walked off the job in the morning in Boston, Massachusetts October 8, 2013. Boston Mayor Thomas Menino vowed to punish school bus drivers who walked off the job on Tuesday in a labor action the city contended was illegal, and which even the drivers' union organization condemned. Some 33,000 public and private school students were left to find alternative routes to school on Tuesday after a union representing some 700 drivers and also represented by the United Steelworkers of America Local 8751 did not show up for work. REUTERS/Brian Snyder (UNITED STATES - Tags: BUSINESS EMPLOYMENT TPX IMAGES OF THE DAY)