Washington, D.C., workers discovered an abandoned sewer line over 100 years old at risk of collapse, prompting lane closures.

Northbound 14th Street NW lanes between L Street and Thomas Circle were closed after the sewer line was discovered. The line was supposed to have been sealed with concrete half a century ago, but for unknown reasons wasn’t. DC Water warned of an “imminent collapse” of the brick-lined sewer if action wasn’t taken immediately.