SAN DIEGO (FOX5/KUSI) -- The National Transportation Safety Board is asking Caltrans to conduct a vulnerability assessment on the Coronado Bridge. An investigation launched by the board a year after the deadly collapse of the Francis Scott Key Bridge in Baltimore shows that 68 bridges have an un known level of risk of collapse because the bridges were built before 1991 when upgraded guidance was released. San Diego’s ‘hotel room tax’ increases soon The NTSB says the report does not mean the Coronado Bridge or the 67 others will collapse, but it wants Caltrans and other bridge owners to conduct vulnerability assessments and create a comprehensive reduction plan if there appears to be a risk higher than the guidance threshold. “This vulnerability assessment is essentially a mathematical risk model used to determine how susceptible a bridge is to collapse from vessel collision and it’s not new," said Jennifer Homendy, chair of NTSB. Officials said their investigation into the deadly Francis Scott Key Bridge collapse determined that running a vulnerability assessment would have allowed Maryland officials to take proactive measures to reduce the risk of a collapse. “Had they ran the calculation on the Francis Scott Key Bridge, the MDTA would have been aware that the bridge was almost 30 times greater than the risk threshold AASHTO (American Association of State Highway and Transportation Officials) sets for critical essential bridges, 30 times greater," said Homendy. She added it was almost 15 times greater for Pier 17 where the ship struck. San Diego History Center archives show that the Coronado Bridge was built 200 feet high and at a curve to accommodate large ships in the San Diego Bay. Nonetheless, NTSB leaders the board needs action. “Public safety depends on it,” said Homendy. The board also recommends that the Federal Highway Administration, Coast Guard and Army Corps of Engineers create a team to help bridge owners evaluate and reduce the risk, which could mean upgrades or changes to operations. FOX 5/KUSI reached out to Caltrans, which owns the Coronado Bridge, for a response. ...read more read less