Mobile phones and social media can be potent tools for members of the public to circulate news and information during natural disasters. Using in-depth interviews, this study examines the case of a citizen collective to understand the interconnections between citizen journalism, mobile devices, and social media in disaster response, particularly in the Global South. Specifically, we investigate how mobile devices helped a prominent citizen collective to witness the 2015 South Indian floods and to share crucial news and information on social media. Our findings reveal that while mobile phones and social media enabled citizen journalists to gather, verify, and relay news during the floods, these technologies were unable to sufficiently challenge caste, class, and urban-rural inequalities in disaster response. We also demonstrate that the concept of witnessing developed by Peters provides a useful framework to study the production of journalism by citizen collectives in extraordinary times.