I spotted another mysterious X on a seemingly vacant home in Massachusetts yesterday. Have you ever seen one of these markings? Have you ever wondered what the X indicates?

There are two types of X's. There's the spray paint version, and then there's the X in a box version. The box version usually contains the colors red and white. The spray painted X is commonly mistaken for graffiti, but it isn't, it's the FEMA Urban Search and Rescue marking system. The “X” is part of a standardized method to indicate the status of a building after a disaster such as a hurricane, earthquake, or fire.

What Does That 'X' Mean On Dilapidated Mass. Homes?

The X in a box may appear ominous, but it can save lives. If a home, business, or any structure is marked by a red and white X, it has been deemed unsafe. It is a simple, visual language developed through necessity, widely recognized among emergency professionals, yet largely invisible in meaning to the general public.

A red X does not mean that the building is in immediate danger of collapse. Also, a building with an X on it does not indicate that an owner has not paid their taxes, nor does it mean that the property is not insured.

Pittsfield Fire Deputy Chief Neil Myers, in a conversation on the radio a few years ago, referenced the fact that the cold storage building fire in Worcester, MA in December of 1999 was a vacant building.

The building was not marked and reports of homeless people trapped inside subsequently sent firefighters inside to look for them.

Six firefighters perished in that blaze.

"That's why we use those X's, so we don't lose firefighters."