Unions on strike question is posed.

I have a problem to solve: I am the newly named CEO of a large Fortune 500 company.  This company has been publicly traded on the NYSE for many years and is well known with the average investor.  The company is currently having a difficult time with its earnings.
The 3 unions that represent 90% of the hourly workforce have voted to strike on the first day of the nest month.  The workers are unhappy about the hours of work; they allege that they are required to work too much overtime and thus this creates a safety hazard in the workplace.  The contracts expired last month and the union was not willing to continue to work under the existing contracts due to these conditions.
What should I do?