A history of the Francis Scott Key Bridge in Baltimore

FILE-An outbound cargo ship passes under the Francis Scott Key Bridge, March 9, 2018 in Baltimore, Maryland. (Photo by Mark Wilson/Getty Images)

The Francis Scott Key Bridge in Baltimore has a storied history dating back to its construction in the late 1970s. Here's more background on the structure. 

  • The Francis Scott Key Bridge opened in March 1977 and is the furthest of the three toll crossings of Baltimore's Harbor. Upon completion, the bridge structure became the final connection to Interstate 695 (the Baltimore Beltway), according to the Maryland Transportation Authority (MDTA). 
  • The 1.6 mile Key Bridge crosses over the Patapsco River and is named after Francis Scott Key, who wrote the U.S. national anthem, the "Star Spangled Banner."
  • In the 1960s, the Baltimore Harbor Tunnel (Interstate 895), the first crossing of Baltimore's Harbor, had reached its traffic size, and drivers faced traffic backups and delays each day during rush hours. 
  • The bridge cost an estimated  $110 million and represented the best option for drivers because it allowed for more traffic lanes and carried lower operating and maintenance costs than a tunnel. 
  • The MDTA notes that the bridge provides a route across the Baltimore Harbor for vehicles transporting hazardous materials (these materials are prohibited from both the Baltimore Harbor and Fort McHenry [Interstate 95] tunnels).

RELATED: Baltimore Key Bridge collapse live updates: Search and rescue continues

What condition was the Key Bridge in?

The most recent federal data shows the bridge was rated as being in fair condition overall before the crash.

The Federal Highway Administration rates bridges on the condition of their individual components. In a national bridge inventory released in June, inspectors rated the Key Bridge’s deck, substructure and superstructure — or the component that absorbs the live traffic load — as satisfactory.

This story was reported from Washington, D.C. The Associated Press contributed.