From Harvard's brief history of the Loeb Classical Library:
In 1939 World War II broke out in Europe. Although the ambitious Loeb Classical Library publishing schedule continued, the war hindered efforts to import books from England, making new editions difficult to obtain in America. While 38 new volumes were published from 1939 to 1945, they were not always available in the United States, particularly as the war dragged on. Only 10 of these 38 new volumes were published in the last three years of the war, an average of about three a year (considerably fewer than the approximately 10 per year average in the early and mid-1930s). In 1944 there were no new volumes added to the Loeb Classical Library, making it the first year without a new edition since the Library’s founding.
The war also had a direct impact on Loeb Classical Library stock. In the late spring of 1940, approximately 200,000 volumes sat in the London warehouse of J. Burn & Company. Until this time, shipments to the United States had been made in small batches of several thousand at a time, but as prospects for England looked increasingly grim, William Smith (then Business Manager at Harvard University Press) placed a substantial order of 122,675 volumes to be shipped to the United States. On the treacherous trip across the Atlantic, one ship with over 9,000 volumes on board was sunk by a German U-boat. The rest arrived safely, adding 113,032 volumes to Harvard University Press’s stock.
This Loeb Classical Library shipment arrived just in time. On July 10, 1940, the Germans began a protracted air attack on Britain and in the autumn of 1940, a bomb hit the J. Burn & Company warehouse, destroying nearly half the Loeb volumes housed there. In 1941 another German bomb hit the same spot, destroying the remaining volumes and leaving Heinemann’s stock nearly depleted. Meanwhile, in the United States, Harvard University Press continued to sell the volumes that William Smith had rescued and sales actually increased during the war. By the war’s end, however, Harvard had also run out of stock on 158 of the 369 volumes that had been published to date, with no way to reprint or restock from England.
That's a hell of a vivid image, isn't it? Imagine working to translate, publish, manufacture, and ship our inheritance from ancient western civilization while the barbarians' bombs fall around you, and the future of western civilization doesn't look anywhere near certain.