Trains on the N-Judah line were stopped near Fillmore and Duboce streets around 10 a.m. as PG&E and fire crews responded to a half-inch gas line rupture caused by a third party digging in the area, PG&E spokeswoman Tamar Sarkissian said.
One Muni rider who was on an inbound N-train was asked to exit the light-rail vehicle along with dozens of other riders at about 10 a.m. just past Carl Street and Hillway Avenue.
The driver explained that he couldn't go any farther because of a gas leak at Church Street and Duboce Avenue.
Another N-Judah train pulled up a few minutes later and let everyone off, adding dozens more passengers to those already stranded on Carl Street.
Many frustrated riders walked a few blocks to Lincoln Way to catch an inbound 71-Haight-Noriega bus, which quickly filled to capacity and skipped most of its regular stops along Haight Street, bypassing growing crowds who were presumably also looking for an alternate route to the N-Judah.
Utility crews worked to pinch off the line, and the flow of gas was stopped around 10:50 a.m., Sarkissian said. Repairs were expected to be completed by noon, she said.
Trains started to resume regular service around 11 a.m., Muni spokesman Paul Rose said.
Rose said the N-Judah line was the only Muni route affected by the incident. He said bus shuttles would continue to operate as service got back to normal.