  A two-neutron unbound excited state of $^{24}$O was populated through a
(d,d') reaction at 83.4 MeV/nucleon. A state at $E = 715 \pm 110$ (stat) $\pm
45 $ (sys) keV with a width of $\Gamma < 2$ MeV was observed above the
two-neutron separation energy placing it at 7.65 $\pm$ 0.2 MeV with respect to
the ground state. Three-body correlations for the decay of $^{24}$O
$\rightarrow$ $^{22}$O + $2n$ show clear evidence for a sequential decay
through an intermediate state in $^{23}$O. Neither a di-neutron nor phase-space
model for the three-body breakup were able to describe these correlations.
