When the Army turned the abandoned Fort De Soto reservation on Mullet Key into a bombing and gunnery range during the Second World War, it did so for one nearby reason: the enormous bomber training base that had risen across the water. That base was MacDill Field, and the men who rained practice bombs and machine-gun fire onto Mullet Key were learning a trade that, in Tampa Bay, had become notoriously deadly to learn.
The installation was dedicated on the 16th of April, 1941, as Southeast Air Base, Tampa, on the Interbay peninsula that reaches south into the bay below the city. It was soon renamed MacDill Field for Colonel Leslie MacDill, a pioneer of military aviation killed in a crash years before. With the United States sliding toward war, MacDill's purpose was singular and urgent: to take raw aircrews and turn them into bomber crews. Transitional training on the four-engine B-17 Flying Fortress began that spring, and the base became the headquarters of the Third Air Force and its bomber command, the funnel through which thousands of fliers passed on their way to the war in Europe.
The phrase that has clung to MacDill ever since came from its hardest chapter, the training of crews on the Martin B-26 Marauder. The Marauder was fast and effective but unforgiving, a “hot” airplane with stubby wings and high landing speeds that punished inexperience, and it earned the nickname “Widowmaker.” So many young pilots ended their training flights in the waters of the bay that the fliers coined a grim saying: “One a day in Tampa Bay.” Historians are careful to note the literal claim was an exaggeration, but the danger was real. By careful count, thirteen Marauders ditched in Tampa Bay in the fourteen months between August 1942 and October 1943, and one stretch saw as many as fifteen accidents in a single month. The bay floor still holds some of those wrecks.
Training a bomber crew meant more than keeping the plane in the air; it meant bombardiers who could hit a target and gunners who could shoot. For that the base needed ranges, and the cluster of low, empty islands at the mouth of the bay was ideal: government-owned, uninhabited, ringed by water. Mullet Key, with its abandoned fort, became one of those ranges, a sub-installation of MacDill where crews practiced bombing and aerial gunnery. The decades-old concrete of Battery Laidley and the quiet beaches of the old reservation absorbed the practice ordnance of a generation learning to fight, which is why, long after, the ground and shallows of the island still yield fragments of that work.
MacDill trained on the heavy B-17 and the medium B-26, and by late in the war it transitioned again to the giant B-29 Superfortress. Nine of the twelve B-26 combat groups that fought in Europe were activated or trained at MacDill, and in combat that supposedly lethal airplane went on to post the lowest loss rate of any American bomber, a vindication of the hard training given over Tampa Bay. The base survived the war and became, in time, MacDill Air Force Base, still active today. But its wartime shadow falls directly on Mullet Key, for the island's modern military chapter was written not by its own old guns but by the bombers of the base across the bay.