An exclusive report by law enforcement reporter Claudia Lauer and reporter Jake Offenhartz uncovered a critical safety measure that was missing when the Key Bridge collapsed in Baltimore, killing six people.

Lauer worked with Offenhartz to begin trying to understand what happened — and what, if any, warning the workers should’ve had. The duo, working with U.S. reporters Mike Kunzelman, Mike Catalini and Becky Boone, would learn the frantic warnings by police of an impending collapse didn’t reach the workers.

The story was exclusively reported by AP and was picked up widely by both local outlets in Maryland and across the U.S. and generated thousands of views on APNews.