Natural or human-made disasters could do huge damage in urban areas and eventually could take lives. It is fundamental to get knowledge of the event's characteristics to dispose of hasty information to help affected people or to prevent all the citizens from the danger zone, and then it will get time to respond to the crisis. Internet of Things (IoT) has a big impact on this kind of situation because a large amount of data through different devices could provide information about the situation, and about the people that are involved in the crisis. In a disaster, one of the big problems adding to the principal crisis is the disinformation, for that reason is necessary to have available and trusty data in case of disaster, also to know the data that provided the information system. To inform the affected people around the crisis event, there is exist some previous works that have used data from sensors, social networks text, or images, to finally be processed. This paper aims to review study-cases where cities implement crisis management platforms, focus on IoT environment where applications use hybrid data to be processed to help citizens in a crisis situation.