A firefighter's jacket and helmet sit on a marker outside Mount Zion African Methodist Episcopal church, early Wednesday, July 1, 2015, in Greeleyville, S.C. The African-American church, which was burned down by the Ku Klux Klan in 1995, caught fire Tuesday night, June 30, 2015. (Veasey Conway/The Morning News via AP)

A spate of fires at black churches in recent weeks -- some of which are being investigated as arson -- are raising questions as to whether the churches are being targeted for hate crimes.

There's no question that one church fire is too many, especially if that fire was deliberately set in an attempt to terrorize a particular community. But speaking more broadly, church fires are a relatively common occurrence, as data from the National Fire Protection Association, a non-profit group that researches fire prevention and safety, show.


Over the period from 2007 to 2011, the group estimates that there were an average of 1,780 fires at churches, funeral homes, and other religious institutions per year. That works out to about 34 per week. And approximately 16 percent of those fires -- 285 per year, or about 5 per week -- were set intentionally.

But there's a lot of nuance to unpack here. "Fire," by the NFPA's definition, can mean a lot of things -- anything from an accidental brush fire outside or a contained fire in the kitchen, to a building-consuming blaze. In an average year, 46 percent of all religious property fires are classified as "confined," meaning they're restricted to a small area (a stove or chimney flue) and generally cause little if any property damage.

"It's really important to understand that the majority of these fires are not consuming the whole structure," Marty Ahrens, NFPA's Senior Manager of Fire Analysis Services, said in an interview.

Among intentional fires, though, roughly two-thirds are not contained -- meaning that they spread and cause property damage, often significant. So on average, between 2007 and 2011, roughly 180 intentional fires per year -- 3 per week -- spread and caused damage.

Three major arsons per week at religious institutions still sounds like a huge number, and it is. But in part, that's simply a function of the number of religious congregations in the U.S. -- roughly 350,000 of them, according to an estimate by the Hartford Institute for Religious Research, the research arm of the Hartford Seminary.

The NFPA's numbers don't classify historically black churches separately, nor do they speak to whether intentional fires are hate crimes or not.

NFPA's numbers do show that the long-term trend has been toward a decrease in church fires, from 3,500 in 1980 to 1,700 in 2011. Better safety standards are likely a big part of that decline.

But that decline is not likely to be comforting to a religious community that just lost their place of worship to a fire in a time of heightened racial sensitivity. Marty Ahrens of the National Fire Protection Association urges congregants and ministers concerned about church safety to consult the following two resources: FEMA's Guide to Developing High-Quality Emergency Operations Plans for Places of Worship, and the Threat Assessment Guide for Houses of Worship, published by the National Church Arson Task Force in 2000.