In these cases normally I follow a very pragmatic approach, the actions for me when a project is interrupted are the following:
1 - make a meeting to obtain the current status and progress of the project.
2 - Use the meeting also to gathering information about the team motivation and lessons learned, problems, pitfalls, achievements,
and manage the expectations of the team, who knows the project
could loose is a window of opportunity and be canceled in the future.
3 - store all needed information for posterior use.
4 - The pause hopeful will be a good time to reflect on solutions that the project might have, and the possible scenarios in the future, project continuation or cancellation.
5 - if the project starts I foresee a shortage of funds, probably some team members will not be available, so a contingency plan must be prepared before the restart of the project.
6 - Very possible situation is a drastic change in requirements depending on interruption duration or to change of priorities due to the crisis.
I think there are many points to reflect in situations like such, and each business area will have specific domain challenges.