A nearly century-old railroad bridge in west Lincoln collapsed following a fire Monday morning.

An unwatched fire caused a nearly century-old railroad bridge to erupt in flames and collapse early Monday morning, according to Lincoln Fire and Rescue.

Officials have called the collapse of Baltimore’s Francis Scott Key Bridge after a cargo ship rammed into it an “unthinkable tragedy.” Here’s what to know.

The bridge is primarily used for freight trains. No word on the cause of the blaze.