Montano posted photos from the Tuscaloosa Tornado. Looking over the photos I saw a few had damaged buildings with a weird 'X' marking on them. I didn't understand it, so I looked it up! My search took me to the National Urban Search & Rescue (US&R) Response System Rescue Field Operations Guide from the Federal Emergency Management Agency (FEMA). That had the answers I wanted, and a bunch of other curios. For our purposes, the most important section is Section 5.5, 'FEMA Search Assessment Mark...
