Tragic events struck northern Japan in March-April 2011. This note presents a case study of rapid distributed brainstorming for disaster response, involving 275 contributors from 23 countries within a three-day period, conducted among the staff in a multinational company. Factors that appear to have contributed to the success of this brainstorming include: Social media that could be easily appropriated; and employee familiarity with large-scale brainstorming. The formation of this "flash-community" joins other CHI reports to point toward a new genre of rapid large-scale responses to disasters through social media. Copyright 2012 ACM.