On 14 November, at Roosevelt's request, Iowa conducted an anti-aircraft drill to demonstrate her ability to defend herself. Porter, along with the other escort ships, also demonstrated a torpedo drill by simulating a launch at Iowa. This drill suddenly went awry when the #3 torpedo aboard Porter discharged from its tube and headed toward Iowa.[2] William D. Porter attempted to signal Iowa about the incoming torpedo but, owing to orders to maintain radio silence, used a signal lamp instead. However, the destroyer first misidentified the direction of the torpedo and then relayed the wrong message, informing Iowa that Porter was backing up, rather than that a torpedo was in the water.[2] In desperation the destroyer finally broke radio silence, using codewords that relayed a warning message to Iowa regarding the incoming torpedo. After confirming the identity of the destroyer, Iowa turned hard to avoid being hit by the torpedo. Roosevelt, meanwhile, had learned of the incoming torpedo threat and asked his Secret Service attendee to move his wheelchair to the side of the battleship, so he could see.[2] Not long afterward, the torpedo detonated in the ship's wake, some 3,000 yards astern of the Iowa. Iowa was unhurt, but trained her main guns on William D. Porter out of concern that the smaller ship might have been involved in some sort of assassination plot.[3]