  The Galactic center supermassive black hole, Sgr A*, has experienced a
strong, unprecedented flare in May 2019 when its near-infrared luminosity
reached much brighter levels than ever measured. We argue that an explosive
event of particle acceleration to nonthermal energies in the innermost parts of
the accretion flow---a nonthermal bomb---explains the near-IR light curve. We
discuss potential mechanisms that could explain this event such as magnetic
reconnection and relativistic turbulence acceleration. Multiwavelength
monitoring of such superflares in radio, infrared and X-rays should allow a
concrete test of the nonthermal bomb model and put better constraints on the
mechanism that triggered the bomb.
