LaSalle was one of three streets in Chicago to have a tunnel under the Chicago River, the other two being W. Washington St. and W. Van Buren St. Constructed in 1869-71, the long tunnel alleviated interruptions from bridge openings due to heavy river traffic and served as an escape route during the Great Chicago Fire of 1871. Originally open to only pedestrians and private vehicles, the LaSalle tunnel was turned over to cable car companies in the 1880s, since it was impossible for cable car systems to span the movable bridges. Closed in 1906, the tunnel was deepened and reopened to electric street car traffic in 1911-12. The tunnel was closed permanently in 1939 to make way for subway construction.