Julia Hyman, 27, was apparently checking whether the coast was clear when she was shot by Shane Tamura on Monday

The last of the Park Avenue mass shooter’s final victims was in temporary safety in a panic room, only to be killed when she stepped outside of it during a lull in the gunfire, police sources and authorities said.

Julia Hyman sought refuge in a panic room during a Midtown mass shooting but was fatally shot by gunman Shane Tamura.