Branch shrinking

So tomorrow, another employee is giving notice to go work for another company.

Business is booming, better pay, and he will get to work locally. He was promised all that by my manager to come work with us, I wasn't aware until recently, and now that our manager has proven to be a liar, he's leaving.

My co workers are now down to one really good technician and two dumbasses, one of which has been looking for a job but cant find one because he needs more experience.

I'm hoping to find another job soon. Need a safety net for when this crashes and burns.