  We discuss properties of three-particle Dalitz distributions in coupled
channel systems in presence of triangle singularities. The single channel case
was discussed long ago where it was found that as a consequence of unitarity,
effects of a triangle singularity seen in the Dalitz plot are not seen in
Dalitz plot projections. In the coupled channel case we find the same is true
for the sum of intensities of all interacting channels. Unlike the single
channel case, however, triangle singularities do remain visible in Dalitz plot
projections of individual channels.
