LYNN – A 12-foot by 16-foot sinkhole swallowed part of Shepard Street at South Common Street Friday afternoon with a Water and Sewer Commission foreman blaming the mess on a collapsed sewer line.The hole measured at least 10 feet deep and it halted traffic at Shepard and South Common at 1 p.m. as Water and Sewer and National Grid crews set up wooden barriers and a crowd formed outside nearby Cibao Market.Connor Holland, who was riding his bicycle on Lynn Common when the collapse occurred, said, “A car drove through and the next thing you know, the entire road just caved in.”Sewer Foreman Michael Biasetti said an initial investigation indicated a 12-inch-wide sewer line probably made of clay and more than 100 years old collapsed under the intersection some time ago. The pipe failure loosened dirt under the street and the road surface until a collapse occurred.”Everything falls into the hole,” Biasetti said.Biasetti said Friday’s wet weather may have contributed to the collapse. He also said the collapse spelled a narrow miss for an unidentified driver who drove through the intersection just before the collapse occurred.”It was a miracle she didn’t fall inside, said Dati Rivera, a Revere resident who was among the spectators staring at the hole.South Common Street resident Jen Caruso planned to run an errand Friday afternoon but decided against driving after seeing the sinkhole. The collapse is not a first: An aging sewer line buckled under Neptune Boulevard several years ago at Blossom Street, partially swallowing a truck.