While investigators probe the cause of a fire that destroyed a rural black church in South Carolina, statistics show church fires aren't unusual and happen dozens of times a week across the nation.

Estimates from the National Fire Protection Association indicate that in the five years from 2007 through 2011, 31 houses of worship burned each week across the country. Arson was relatively rare, reported in only 16 percent of those fires.

Investigators are looking into what caused a fire Tuesday night at Mount Zion African Methodist Episcopal Church in Greeleyville. The same church was torched by members of the Ku Klux Klan 20 years ago.

A federal official has told The Associated Press that preliminary indications are that this week's fire was probably not arson. The official spoke on the condition of anonymity, because he wasn't authorized to discuss the case publicly.