The flat-spectrum radio quasar 3C 454.3 underwent an extraordinary 5-day gamma-ray outburst in November 2010 where the daily flux measured with the Fermi Large Area Telescope (LAT) at photon energies E>100 MeV reached (66+/-2) x 10^-6 ph cm^-2 s^-1. The 3-hr peak flux corresponded to an apparent isotropic luminosity of (2.1+/-0.2)x10^50 erg s^-1, the highest ever recorded from a blazar. In this talk we review the features of this exceptional event as measured by the Fermi LAT and discuss their implications.