Ah - now I understand my confusion. It doesn't happen every year, but it's a semi-regular occurance among the sites in Israel. Here's a few examples...
Dec 2007, Church of the Nativity
April 2003, Church of the Sepulchre
Jul 2002, Church of the Sepulchre
***Dec 2007, Church of the Nativity***
Didn’t one here spark the Crimean war?