While educators’ uses of social media for purposes such as professional learning and networking are now well-established, our understanding of how educational institutions use social media—especially to engage key stakeholders during periods of crisis—is limited. In this study, we used a public data mining research approach to examine how K-12 school districts in the United States used Twitter as a communication tool during a critical period of the COVID-19 pandemic, March-April, 2020. Through a three-step grounded theory approach of 1,357 district tweets from 492 school districts, we found that the themes of messages fell into three categories, announcements, community oriented, or unrelated. Announcements were more common during the early stages of the pandemic (and were engaged with more collaboratively), with community-building posts more common later on. This study demonstrates the potential of district social media use as a communication platform and a means to impact public perceptions and support.