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FEMA search assessment markings

2021-May-09

What do those weird crosses on damaged buildings mean?

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 Marking' on pages 6-6 and 6-7.

Search assessment markings

Search and rescue teams mark buildings to tell other teams if they're in the building, if they've left, and what they found. The guide isn't explicit, but I assume this is to make sure buildings (especially dangerous ones) don't get searched twice.

The markings are about 60 cm high so they can be clearly read at a distance.

Entry marks

Teams spray a single slash at 45 degress, top-left to bottom-right. They write their team name and date and time of entry to the left of the slash. It shows that the team is currently searching the building.

A single slash from the top-left to the bottom-right with the team name, entry date, and entry time written to the left of centre.

The FEMA search assessment marking for entry into a building.

Exit marks

The team crosses the first slash at 45 degrees, top-right to bottom-left. They write the date and time of exit above the cross. It shows the team is no longer in the building.

A cross with the team name, entry date, and entry time written to the left of centre. The exit date and time is written above the cross.

The FEMA search assessment marking for exiting a building.

The guide isn't explicit on this, but this is clearly distinct from the entry marking. Another team can look at the marking and see if a team is still inside. If they've been in there a long time (i.e. they're trapped), then the second team knows how long they've been trapped. They can decide to go in after the trapped team.

Extra notes

The search and rescue team writes extra information in the remaining spaces of the cross. They write any hazards to the right of the cross, and number of survivors and dead found below the cross.

A cross with the team name, entry date, and entry time written to the left of centre. The exit date and time is written above the cross. They write hazards to the right and survivor and death counts below.

The complete FEMA search assessment marking.

The guide uses the suffixes L and D for "living" and "dead". So 5 survivors and 2 dead would be written under the cross as:

5L
2D

The guide uses "rats" as a hazard in the example, but there could be plenty of others, like natural gas, live power, and so on.

While not in the guide, it looks like teams make sure there is always something in each space. For example, if there are no hazards they might write a 0. Same for no survivors or dead found.

Other markings

The guide adds to these basic marks for:

  1. New search completed: Mark out the cross with a plus-shape and write a new cross.
  2. Search incomplete: Put a filled circle on the centre of the cross. Add notes (e.g. areas searched) in a box below.

None of these are visible in the photos Montano posted.

Conclusion

A neat solution to a problem I didn't know existed.

It reminds me a little bit of shared variable locks. Putting the first slash down is like taking the lock. Crossing it is like releasing the lock. Some locks have extra detail, like a timeout; so do these markings.

The guide also has other interesting things, like structure assessments, how to run medevac, helicopter hand signals, how to set up a "base of operations" (comically, the "BOO"), and so on. All morbidly interesting.