On July 30, 1916, the Black Tom munitions depot exploded, rocking New York Harbor and sending sleeping residents tumbling from their beds. The noise was heard as far away as Maryland and Connecticut. On Ellis Island, terrified immigrants were evacuated by ferry to the Battery. Shrapnel pierced the Statue of Liberty, and the arm of the Statue was closed to visitors afterward. Property damage was estimated at $20 million, and it is not known how many died. According to historians, Germans sabotaged the Lehigh Valley munitions depot to stop deliveries being made to the British, who had blockaded the Germans in Europe. The site saw one of the worse acts of terrorism in American history.