During a crisis, especially in catastrophic situations, many people from many organisations gather, physically at the location of the crisis or virtually through different networks to try to cope with the situation. First responders are the people on the ground where the event occurs and they are also part of this network. This creates a virtual organisation that will last for the response and recovery time of the crisis. Organising this ad-hoc network of people and organisations, coordinating actions, sharing and making sense of the information that is produced is a challenge that resonate with the challenges of virtual enterprises but at a different pace and sometimes with moving goals. In this talk, we will cover the issues related to coordination and information sharing that occurs during a crisis. We will address them first from a social science perspective and then with an information system perspective. Then we will present recent information system and computer science work that aim at supporting collaboration between people and try to make the link with more traditional virtual enterprise. We will show how this opens new research perspectives and call for adequate methods that requires close collaboration between social scientists, practitioners and computer scientist on the long run.