On Monday, a giant tornado swept through the suburbs of Oklahoma City, leaving more than 90 dead, and destroying schools and neighborhoods completely. Now stars such as Katy Perry, Pitbull and Kristen Bell have taken to Twitter to make their fans donate money to American Red Cross.American Red Cross has opened several shelters for the victims, and now the stars are hoping to have their fans help as well. "Let's help, just text Redcross to 90999 to donate 10 dollars to those in need", Katy Perry tweeted.