A gas leak that lasted more than three hours and led to an evacuation near Center and Maple Avenue in Warsaw was caused indirectly by a crumbling storm sewer pipe.

The leak began around 10 a.m. while city street department employees were working to repair the underground storm sewer pipe that was unstable and leaning against a gas line at the corner of Center and Maple.

The worker, using a backhoe, bumped some concrete that was part of the storm water structure.

“Evidently, it sheared the pipe right off,” said Mayor Joe Thallemer, who said he remained on sight during the leak.

Repairs were slowed because the 3-inch gas main had four feeds, Thallemer said.

Three plastic feeds were soon crimped, but shutting off gas from the fourth feed – made of metal – required equipment that had to be delivered from Plymouth, Thallemer said.

NIPSCO made the repairs.

The leak was big enough that it could be heard hissing nearly a block away, according to a neighbor.

The decision to evacuate the immediate area came after officials realized the leak could not quickly be contained. City officials, in the meantime, encouraged anyone affected by the accident to visit the Pete Thorne Center.

Center Street was closed between Scott and Bronson streets. Portions of Market and Main streets, which run parallel to Center, were also closed temporarily near the scene.

A small leak continued until about 1:15 p.m., Thallemer said.

Thallemer said it was probably the biggest gas leak in Warsaw in recent memory.

The repair work was not related to ongoing sanitary sewer maintenance work that began this summer and is continuing.