JTA — Unknown vandals overturned about 40 gravestones at a Jewish cemetery in Hartford, Connecticut.

The damage at the Congregation Ados Beth Israel Cemetery took place sometime between October 12 and October 19, according to the Associated Press.

The attack was discovered by a man who regularly visits the grave of his son, who was killed while serving in the US military, according to WTNH television news.

The cemetery superintendent told police that repairing the damage would cost more than $20,000.

The gravestones were knocked off of their bases, including one large stone which would have taken at least two people to topple, WTNH reported.

The damage occurred throughout the cemetery.

Times of Israel staff contributed to this report.