During World War II, the US kept radio silence about military information including weather. The government was aware that German U-boats patrolled the coastal waters. Hurricane-warning flags were posted at coast guard stations and post offices. But weather forecasters wanted the public to know this was a monster storm. The Hurricane Warning Centers in Miami, San Juan, Washington DC and Boston issued a total of 51 warnings. In New York city alone there were thousands of phone calls made and received between September 12 and 15.