In the early 1930s, plans were made by the state of New York to construct a new highway between the Bear Mountain Bridge and Cornwall-on-Hudson that would bypass both Cornwall-on-Hudson and Highland Falls and bypass the narrow Storm King Highway, US 9W's original routing between the two. On April 8, 1934, three people were killed by a rockslide on the Storm King Highway, expediting plans for the new highway, known as the Storm King Cut-off. The southernmost of the highway—from the bridge to just north of Fort Montgomery—utilized the existing right-of-way of US 9W, which was widened from two to four lanes and straightened through the construction of rock cuts. Construction on this segment was completed in 1937.