"During a planned deploy in one of our core services, we experienced unexpected complications that made Twitter unavailable for many users starting at 11:01am. We rolled back the change as soon as we identified the issue and began a controlled recovery to ensure stability of other parts of the service. The site was fully recovered by 11:47am PDT. We apologize for the inconvenience. "
Twitter had crashed again on March 2 during the Academy Awards, when the company's infrastructure was overwhelmed by a tweets about the Oscar show.