First, talk with family members openly and honestly, including the children, about the situation and what steps are being taken to improve it. Each family member will need to be patient and understand that the financial crisis won't last forever. Secondly, include family members in the decision-making process. At the same time, you'll be teaching your children, by example, how to draw from strengths and develop resiliency. Third, reassure children that they are loved and that the family will not break up.
Children tend to magnify a crisis.
Make sure they understand that they didn't cause the family's financial crisis, and they don't have to solve it themselves.