  We discuss in this Letter the energetics of large gamma-ray superflares
observed from Soft-Gamma Repeater sources. The last recorded event has in fact
ruled out some models for the energy release. For the first time actual
information about a possible associated gravitational wave emission may be
gathered from the LIGO data, even in the case that most of the energy was
emitted in gamma-rays. Even upper limits on the amplitude of the latter $h$ at
the expected frequency $f_{c} \leq 2 kHz$ may be useful to further constrain
the remaining mechanisms
