As they get to the end of the metal rafters that signal the beginning of the bridge the four guards stop and take up positions along either side. Two left, two right - Standing guard as instructed, tucked in behind whatever shelter they could find.
As they cross the bridge Riley looks out over a city that seems for a moment to be peaceful place except for the storm. The swarms were taking shelter somewhere he imagines. But this fantasy is short lived, along with any plans forming where they could have taken advantage of their reluctance to go out in the rain and he watches as an entire bank of the river is suddenly flooded with bodies.
Thousands of them all marching in unison like a military parade along the city streets.