She was to join the escort of USS Iowa, which was conveying President Roosevelt, General Marshall other senior American war leaders to conferences in Cairo and Tehran.
After she joined the escort, one of William D Porter's depth charges fell into the sea and exploded.
The Iowa and the remaining escorts, assuming that the explosion indicated a torpedo attack, took evasive action and began hunting the 'sub'.
On 14 November 1943, at the President's request, Iowa conducted an anti aircraft drill.
The escorting destroyers joined in, carrying out a simulated torpedo launch for the President's edification.
In order to maintain radio silence, William D Porter used a signal lamp in an effort to warn Iowa of the danger.
This would have been fine, if the signals had been any use.
The first one misidentified the torpedo's direction, and the second simply provided Iowa with the baffling information that William D Porter intended to go backwards.
Fortunately, this was enough and the torpedo exploded in Iowa's wake.
I suspect everyone on her bridge would have gladly been blown out of the water by that stage.
Admiral King, chief of the US Navy and a tiny bit irascible even when his own ships *weren't* trying to kill him, did not.
Lawton Dawson, the torpedo rating responsible, was sentenced to hard labour.
President Roosevelt later intervened to reduce his punishment.