  The low-lying level structure of the unbound neutron-rich nucleus $^{13}$Be
has been investigated via breakup on a carbon target of secondary beams of
$^{14,15}$B at 35 MeV/nucleon. The coincident detection of the beam velocity
$^{12}$Be fragments and neutrons permitted the invariant mass of the
$^{12}$Be+$n$ and $^{12}$Be+$n$+$n$ systems to be reconstructed. In the case of
the breakup of $^{15}$B, a very narrow structure at threshold was observed in
the $^{12}$Be+$n$ channel. Contrary to earlier stable beam fragmentation
studies which identified this as a strongly interacting $s$-wave virtual state
in $^{13}$Be, analysis here of the $^{12}$Be+$n$+$n$ events demonstrated that
this was an artifact resulting from the sequential-decay of the
$^{14}$Be(2$^+$) state. Single-proton removal from $^{14}$B was found to
populate a broad low-lying structure some 0.70 MeV above the neutron-decay
threshold in addition to a less prominent feature at around 2.4 MeV. Based on
the selectivity of the reaction and a comparison with (0-3)$\hbar\omega$
shell-model calculations, the low-lying structure is concluded to most probably
arise from closely spaced J$^\pi$=1/2$^+$ and 5/2$^+$ resonances
(E$_r$=0.40$\pm$0.03 and 0.85$^{+0.15}_{-0.11}$ MeV), whilst the broad
higher-lying feature is a second 5/2$^+$ level (E$_r$=2.35$\pm$0.14 MeV). Taken
in conjunction with earlier studies, it would appear that the lowest 1/2$^+$
and 1/2$^-$ levels lie relatively close together below 1 MeV.
