On 12 November, she departed Norfolk to rendezvous with
Iowa (BB-61) the following day. That
battleship was on her way to
North Africa carrying President
Franklin D. Roosevelt to the
Cairo and
Teheran Conferences.
Porter was involved in a major mishap while departing Norfolk when her anchor tore the railing and lifeboat mounts off a docked sister destroyer while manoeuvring astern. The next day, a
depth charge from the deck of
Porter fell into the rough sea and exploded, causing
Iowa and the other escort ships to take
evasive maneuvers under the assumption that the task force had come under
torpedo attack by a
German U-boat.
[1] On 14 November, at Roosevelt's request,
Iowa conducted an anti-aircraft drill to demonstrate her ability to defend herself. The drill began with the release of a number of balloons for use as targets. While most of these were shot by gunners aboard
Iowa, a few of them drifted toward the
William D. Porter which shot down balloons as well. The
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
William D. Porter discharged from its tube and headed toward
Iowa.
[1] William D. Porter attempted to signal
Iowa about the incoming torpedo but, owing to orders to maintain
radio silence, was forced to use a
signal lamp. 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 telling her that a torpedo was in the water.
[1] 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.
[1] 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 may have been involved in some sort of assassination plot.
[2] Following these events, the
William D. Porter's captain, and her entire crew, were placed under arrest - the first time in U.S. Navy history that this had occurred. The ship and her crew were ordered to Bermuda for an inquiry into the
Iowa affair. Captain Walker and several of his officers were sentenced to shore duty in obscure locations. Torpedoman Lawton Dawson, whose failure to remove the torpedo's
primer had enabled it to fire at
Iowa, was sentenced to
hard labor, though President Roosevelt intervened in his case, as the incident had been an accident.
[3] A week later,
William D. Porter returned to Norfolk and prepared for transfer to the
Pacific. She got underway for that duty on 4 December, steamed via
Trinidad, and reached the
Panama Canal on the 12th. After transiting the canal, the destroyer set a course for
San Diego, where she stopped between 19 and 21 December to take on cold weather clothing and other supplies necessary for duty in the
Aleutian Islands.