Social media is changing the narrative during crisis events. It has facilitated citizen-led emergency dispatch and rescue; organized food and clothing drives; and served as a platform to share and receive life-saving information. However, during the 2014 Napa Valley Earthquake, while some communities were more active online than ever before, some went silent. Why would this be? Controlling for demographic characteristics and earthquake intensity, this study investigates the effect bonding, bridging and linking social capital had on hyperlocal social media use following the earthquake and its aftershocks. Using a quantitative cross-sectional longitudinal study across 121 Nextdoor online neighborhoods in California’s Napa Valley region across 42 days in August and September of 2014 (N=3,570), I find that bridging and linking social capital and online communication via Nextdoor operate in parallel. This finding comes with an important practical implication, namely, that social media can provide access and activate bridging and linking ties that can expedite collective action in a time of need. The theoretical implications of this research confound the claims that increased internet use leads to less social engagement (Nie 2001, Nie and Erbring 2002, Kraut et al. 1998, Putnam 2000).