  Recently Fuller & Shi proposed that the gravitational collapse of
supermassive objects ($M \gtrsim 10^4M_\odot$) could be a cosmological source
of $\gamma$-ray bursts (GRBs). The major advantage of their model is that
supermassive object collapses are far more energetic than solar mass-scale
compact mergers. Also, in their proposal the seeds of supermassive black holes
(SMBHs) thus formed could give rise to the SMBHs observed at the center of many
galaxies. We argue here that, besides the generation of GRBs, there could well
occur a strong generation of gravitational waves (GWs) during the formation of
SMBHs. As a result, the rate of such GW bursts could be as high as the rate of
GRBs in the model by Fuller & Shi. In this case, the detection of GRBs and
bursts of GWs should occur with a small time difference. We also argue that the
GWs produced by the SMBHs studied here could be detected when the Laser
Interferometric Space Antenna (LISA) becomes operative.
