The Baltimore bridge collapse raised questions about key safety features — experts say better ones may not have helped

• The Francis Key Bridge collapse has ignited debates about the safety of America's infrastructure. 
• Experts question whether the bridge's age meant protections were out of date.  
• Some think the impact was a freak accident that couldn't have been mitigated. 

The 984-foot container ship that caused the Francis Scott Key Bridge to collapse has raised questions about whether the structure could have been saved.

The Key Bridge, Baltimore's biggest bridge and a critical piece of infrastructure for the city, finished construction in 1977.