  We discuss the possibility that production of final states with bottomonium
and light mesons at the peak $\Upsilon(6S)$ in the $e^+e^-$ annihilation at
approximately 11.00 GeV is in fact due to a triangular singularity at the
threshold of the heavy meson pair production $B_1(5721) \bar B + c.c.$ through
the process $e^+e^- \to B_1(5721) \bar B \to Z_b(10610) \, \pi$. The presence
of the hidden-bottom resonance $Z_b(10610)$ then explains the observed enhanced
production of the final channels with both ortho- and para- bottomonium states,
$\Upsilon(nS) \pi \pi$ and $h_b(kP) \pi \pi$. The discussed mechanism also
predicts a distinct pattern for production of hidden-bottom states at the
$\Upsilon(6S)$ energy that can be tested by experiment.
