Key TakeawaysBoeing's largest labor union rejected its latest contract offer and voted in favor of starting its first strike in over a decade.The strike started at midnight, with workers picketing Boeing facilities early Friday morning.The company said it remains committed to "resetting our relationship" with the union and workers. Boeing (BA) shares fell in pre-market trading Friday as the company's largest labor union partner voted to reject Boeing's latest contract offer and started its first strike in o ...