User participation is vital to the success of collaborative crowdsourcing platforms such as Wikipedia. Previously user participation has been studied during “normal times”. However, less is known about participation following shocks that draw attention to an article. Such events can be recruiting opportunities due to increased attention; but can also pose a threat to the quality and control of the article and drive away newcomers. We study the collaborative dynamics of Wikipedia articles after times corresponding to shocks generated by drastic increases in attention as indicated by data from Google trends. We find that participation following such events is indeed different from participation during normal times–both newcomers and incumbents participate at higher rates during shocks. We also identify collaboration dynamics that mediate the effects of shocks on continued participation after the shock. The impact of shocks on participation is mediated by the amount of negative feedback given to newcomers in the form of reverted edits and the amount of coordination editors engage in through edits of the article’s talk page.