over the creek) to connect Hawkins Point to Sollers Point. (At the same time, a bridge was planned for the segment of an additional through highway for the East Coast with I-95 that would run through the city near Fort McHenry and paralleling the now two decades old Harbor Tunnel Thruway; this was replaced by what is now known as the Fort McHenry Tunnel, a major expensive project four-tube facility running under and curving around historic 1798 Fort McHenry that opened in 1985). Contractors took bearings of the outer harbor bottom and ship channel in the spring of 1969. Bids for construction of the proposed tunnel were opened on July 30, 1970, but price proposals were substantially higher than the engineering estimates. Officials drafted alternative plans, including the concept of a four-lane bridge. The bridge, at an estimated cost of $110 (USD) million, represented the best alternative because it allowed for more traffic lanes and carried lower operating and maintenance costs than a tunnel. In addition, a bridge would provide a route across the Baltimore Harbor for vehicles transporting hazardous materials (these materials are prohibited from both the Baltimore Harbor and Fort McHenry tunnels). Construction began in 1972, and the bridge opened to traffic on March 23, 1977. Including its connecting approaches, the bridge project is in length. Other structures along the thruway include a dual-span drawbridge over Curtis Creek and two parallel bridge structures that carry traffic over Bear Creek, near the former Bethlehem Steel Sparrows Point plant, this portion of the project not being fully complete until the late 1990s. Located in an area rich with American history, scholars believe the span crosses within of the site, marked in the water off the bridge by a red-white-blue buoy with stars and stripes painted on it, where Francis Scott Key, held aboard an American truce ship with the British Royal Navy fleet witnessed the bombardment of Fort McHenry on the days and nights of September 12-13-14, 1814. That battle and bombardment inspired Key to write the words of the Star Spangled Banner. Located just southeast of the bridge and adjacent underneath are the ruins of the island shoals of Sollers Flats with Fort Carroll, begun building in the 1840s under the supervision of United States Army Corps of Engineers, then Col. Robert E. Lee. There is another bridge called the Francis Scott Key Bridge, located in Washington, DC on