Collaborative crowdsourcing is a well-established model of work,especially in the case of open source software development. Thestructure and operation of these virtual and loosely-knit teams dif-fer from traditional organizations. As such, little is known abouthow their behavior may change in response to an increase in exter-nal attention. To understand these dynamics, we analyze millionsof actions of thousands of contributors in over 1100 open sourcesoftware projects that topped the GitHub Trending Projects pageand thus experienced a large increase in attention, in comparisonto a control group of projects identified through propensity scorematching. In carrying out our research, we use the lens oforgani-zational change, which considers the challenges teams face duringrapid growth and how they adapt their work routines, organiza-tional structure, and management style. We show that trendingresults in an explosive growth in the effective team size. However,most newcomers make only shallow and transient contributions. Inresponse, the original team transitions towards administrative roles,responding to requests and reviewing work done by newcomers.Projects evolve towards a more distributed coordination model withnewcomers becoming more central, albeit in limited ways. Addi-tionally, teams become more modular with subgroups specializingin different aspects of the project. We discuss broader implicationsfor collaborative crowdsourcing teams that face attention shocks.