  We present a study of the first and second switches (SWs) with nearly
identical switching current $I_{\rm SW}$ in
Bi$_2$Sr$_2$Ca$_{0.85}$Y$_{0.15}$Cu$_2$O$_y$ intrinsic Josephson junctions
(IJJs). In contrast to early studies where a large difference between $I_{\rm
SW}^{\rm 1st}$ and $I_{\rm SW}^{\rm 2nd}$ was observed, a crossover temperature
$T_{\rm cr}$ to the quantum phase escapes for the 2nd SW is strongly reduced
$(\sim$2.8~K) and agrees with that for the 1st SW. This confirms that the
anomalous enhancement of $T_{\rm cr}^{\rm 2nd}$, commonly observed in the IJJs
with $I_{\rm SW}^{\rm 1st} < I_{\rm SW}^{\rm 2nd}$, originates from the phase
running state after the 1st SW. Detailed analysis of the microwave-induced
escapes strongly suggests that nonlinear bifurcated phenomena possibly occurs
in IJJs.
