  Origin of enigmatic line profiles of extremely luminous type IIn supernova
SN~2006gy on day 96 is explored. Among conceivable possibilities the most
preferred is the model that suggests holes in the optically thick cool dense
shell (CDS). The line radiation emitted at the inner side of the opaque CDS
escapes through the holes thus producing unusual line profile with the emission
shifted redward. The holes could emerge as a result of a vigorous
Rayleigh-Taylor instability leading to the CDS fragmentation. The model light
curve with the CDS fragmentation is shown to be consistent with the SN~2006gy
bolometric light curve.
