total layoff

from nevada:I work as manager for a restaurant group that use to belong to a large corporation ,this corporation has been sold but the restaurant group still belong to the owner of the corporation.
Early this year the restaurants have been put for sale,the management and employee were told about a program that
would give them a certain amount of money each month
that they would stay until the place is sold,nothing was definitive or on paper,but we were told not to worry,we will be taken care off.They announced a month later that the restaurants were not for sale anymore and that business
was going on as normal,the owner was going to take partners
to run the group.the general manager assured us that we had nothing to worry about.
two days ago we learn (corporate release on the internet)that the same restaurant in washington
has been closed and will be remodeled with a new concept,this concept will be followed in the las vegas restaurant?.we tried to call corporate but the director of operation is nowhere to be found.
I have 70 employee worrying about their future,can they close and terminate all employees without notice? do we have any legal ressources ?
thanks

If you are all considered at-will employees then you have nothing you can do about this situation.