Twenty years after the Ku Klux Klan burned it down, a South Carolina black church, north of Charleston, has caught fire again and authorities are trying to determine why.

This time, the Tuesday night blaze came as storms moved through the area, casting uncertainty over whether the fire was intentionally set.

But the fire at the Mount Zion African Methodist Episcopal church in Greeleyville broke out at a time when federal authorities are investigating conflagrations at several other predominantly black churches, but so far the fires don't appear to be related.

Greeleyville is a town of about 400 people around 50 miles north of Charleston, where a pastor and eight members of a historic black church were fatally shot June 17 in what authorities are investigating as a hate crime.