About an hour past midnight on August 11, 1906, the 398-foot, 3,665-ton steamer Troy rammed the Interstate Bridge, knocking a 200-foot piece of steel into the bay and buckling the northern span, which collapsed, blocking all traffic on the bay and trapping thirty-three ships inside the upper harbor.
Captain Robert Murray had blown the signal on the ship’s whistle (one long, one short, one long) to notify operators to swing the bridge open, but claimed he could not see the bridge well because of the structure’s lighting, which he said “kind of blinds one at night.” He explained to reporters that instead of slowing or stopping, as was required when the bridge failed to open, he didn’t worry that the bridge wasn’t immediately opening for the Troy, claiming “That seems to always be the custom of the bridge.”
The collision did more injury to Murray’s reputation than it did to the Troy, but the bridge was significantly damaged. Clearing the channel took almost a week, costing each trapped vessel’s operators about $1,000 a day. Engineers spent nearly two years restoring the bridge.
The bridge would be wrecked again in 1924. On November 21 captain A. R. Morse accidentally steered the 600-foot, 8,000-ton steamer Merton E. Farr into the Interstate Bridge, the only non-railway bridge connecting Duluth and Superior at the time. Defective steering gear was blamed for the accident. The Farr was loaded with 430,000 bushels of flax, experienced only slight damage to her bow. The next day the Great Northern Railway, which owned the bridge, put eight barges and a crew of 100 men to work to clear the wreckage and rebuild the bridge, a task that was estimated to take between a month and 45 days. According to the Duluth News Tribune, it was an interesting engineering feat: “
The eight barges will be sunk to the bottom of the harbor, four on each side of the span, and cross pieces will be placed under the span and to the sunken barges. Then the water will be pumped out of the barges which, rising to the surface, are expected to float the span.
Meanwhile, other plans had to be made. Several craft became ferry boats, conveying people, wagons, automobiles and even streetcars across the bay, and passenger docks were hastily built on Rice’s Point at the end of the streetcar line.