Storm Dawn391

The honest answer is that EMF detection as a paranormal tool is pretty dodgy. It was originally supposed to detect ghosts based on this theory that spirits create electromagnetic disturbance, but...

The silence might mean nothing. Sometimes the most boring answer is the right one - lights in the woods spooked trained military personnel and they made a meal of it.

Engineering teams found nothing unusual when they checked the tunnels the next day. This is the bit that's most interesting to me. No physical evidence but reliable witnesses.