  We give a rigorous construction of solutions to the Euler point vortices
system in which three vortices burst out of a single one in a configuration of
many vortices, or equivalently that there exist configurations of arbitrarily
many vortices in which three of them collapse in finite time. As an
intermediate step, we show that well-known self-similar bursts and collapses of
three isolated vortices in the plane persist under a sufficiently regular
external perturbation. We also discuss how our results produce examples of
non-unique weak solutions to 2-dimensional Euler's equations -- in the sense
introduced by Schochet -- in which energy is dissipated.
