During the summer months, reception of wireless signals was difficult due to adverse atmospheric conditions that increased static. Long distance communication was possible only during the night for brief intervals. To alleviate this limitation Sayville "quietly" (such that only a few government officials were aware of it) made major improvements to its equipment. In April 1915, the transmitter was upgraded from 35 to 100 kilowatts and three tall antenna towers were installed, transforming it into one of the most powerful transatlantic stations in this part of the world. By May the Telefunken station at Sayville and another at Tuckerton, New Jersey, were accused of sending messages to a German U-boat providing information that allowed the submarine to "ambush" and sink the RMS "Lusitania". This led to greater scrutiny of activity at the station.