...perhaps some heavy object flying off a passing train...
Several "Don't believe in god? You are not alone." billboards erected by the Coalition of Reason have suffered apparent vandalism during a 14 month, 16 city campaign.
Godless billboard heavily damaged in Florida
Examiner.com http://www.examiner.com/x-8947-LA-Atheism-Examiner~y2010m4d13-Godless-billboard-heavily-damaged-in-Florida
'Godless' Florida billboard damaged
WTSP http://www.wtsp.com/news/state/story.aspx?storyid=129743&catid=19
Controversial atheist billboard severely damaged
History City News http://historiccity.com/2010/staugustine/news/florida/controversial-atheist-billboard-severely-damaged-2994