The Army made some of them sick.
In March 1942 the 35th Combat Engineering Regiment had come first to the road. They flooded into and through Dawson Creek, British Columbia, out over the Peace River and on to Fort St John. The stuff of legend, their race against the spring thaw got them to Ft Nelson in the nick of time—just before the winter trail disappeared from under their rolling dozers and trucks.
At Ft Nelson, their equipment all but destroyed, they waited while their commanders struggled to find a route through the Canadian Rockies. And then the soldiers started to get sick.
In March, back at Fort Ord, the Army had hurriedly vaccinated everybody in the regiment to protect them from Yellow Fever. Somebody must have thought that disease prevalent in British Columbia. Or somebody just blindly followed a procedure. Either way they used contaminated vaccine and in May the soldiers of the 35th began coming down with serum hepatitis.
As the number of cases mushroomed, the Army hurriedly constructed Ft. St. John hospital from two prefabricated frame buildings and brought a medical platoon from the 58th medical battalion down from Whitehorse to staff it. Doctors planned to evacuate sick men to the new facility by air. But the Army had far too few airplanes and pilots. After the first 100 evacuees, only the most gravely ill went out to Fort St. John. The rest, as many as 500 men, suffered yellow jaundice, severe weakness and debilitating nausea—in their tents.