Earlier.
She had been sent to check on the patrol that was deployed to check on another group. The first group were a bunch of close quarters specialists who specialized in infantry on infantry warfare. They had been sent to a location under a bridge to find possible routes past enemy lines.
Unfortunately they went radio silent and stayed silent several hours ago. So a patrol was redirected to check on them. But when it started raining the chemical mix, they had decided to take shelter in some building. So when her unit had come across them when the High Priestess asked her to check on them she was livid.
They had kicked it into gear and gone ahead of them. When she arrived to see what was going on she found the current situation. The patrol soldiers were walking around, being careful not to touch anything. Because this would take some investigating to figure out the cause.